Synthesis and activity of bivalent FKBP12 ligands for the regulated dimerization of proteins

BIOORGANIC &

MEDICINAL

CHEMISTRY

Bioorganic & Medicinal Chemistry 6 (1998) 1309±1335

Synthesis and Activity of Bivalent FKBP12 Ligands for the

Regulated Dimerization of Proteins

Terence Keenan, David R. Yaeger, Nancy L. Courage, Carl T. Rollins,

Mary Ellen Pavone, Victor M. Rivera, Wu Yang, Tao Guo,^yJane F. Amara,

Tim Clackson, Michael Gilman and Dennis A. Holt *

Ariad Gene Therapeutics, 26 Landsdowne Street, Cambridge, MA 02139, USA

Received 12 June 1998; accepted 19 June 1998

AbstractÐThe total synthesis and in vitro activities of a series of chemical inducers of dimerization (CIDs) is described.

The use of small-molecule CIDs to control the dimerization of engineered FKBP12-containing fusion proteins has been

demonstrated to have broad utility in biological research as well as potential medical applications in gene and cell

therapies. The facility and ¯exibility of preparation make this new class of wholly synthetic compounds exceptionally

versatile tools for the study of intracellular signaling events mediated by protein±protein interactions or protein locali-

zation. While some congeners possess potency comparable to or better than the ®rst generation natural product-

derived CID, FK1012, structure±activity relationships are complex and underscore the need for application-speci®c

Introduction

the plasma membrane^{9,11,12,15,16,21}and into or out of the

nucleus^9,22have also been eected. In addition, small-

molecule controlled reconstitution of multidomain

transcription factors has provided a direct means of

regulating gene expression^{9,10,21,23±25}and has thus

enabled a medicinally important means of delivering

therapeutic proteins via gene therapy. Toward this end,

pharmacologic control of the production of human

growth hormone in vivo has been achieved using an

orally active small-molecule.^25,26

In a seminal 1993 Science paper, Stuart Schreiber and

long-time collaborator Gerald Crabtree, demonstrating

a powerful union of chemistry and biology, described a

method for inducing the dimerization of arti®cial intra-

cellular protein receptors with cell permeable ligands.¹

This method provided a means of temporally control-

ling speci®c signal transduction pathways and gene

expressions with small-molecules. Since their initial

report, small-molecule induced protein dimerization has

been utilized to study a wide range of intracellular sig-

naling events which are naturally mediated by protein±

protein interactions or protein localization. In this way,

dose-dependent small-molecule control has been

brought over signaling pathways initiated by the T-cell

receptor,^1,2erythropoietin receptor,³PDGF and insulin

receptors,⁴c-kit receptor,⁵Fas,^6±10Src kinase,¹¹Sos,¹²

Raf kinase,^13,14ZAP kinase,¹⁵LMP1,¹⁶and FLICE.^17±19

Clustering of cadherin²⁰and localization of proteins to

The crux of the original Schreiber and Crabtree method

was the use of a semi-synthetic dimer of the natural

product FK506, aptly named FK1012.^1,27By virtue of

its bivalent anity for FK506-binding protein

(FKBP12), FK1012 is a chemical inducer of dimeriza-

tion (CID) which is able to dimerize²⁸or oligomerize

fusion proteins containing one or more FKBP12

domains (Fig. 1).

To date, FK1012 has been the most widely utilized CID,

although related systems based on the natural products

cyclosporin (as a semi-synthetic dimer),^8,9,15coumer-

mycin,¹³and rapamycin^{15,21,23,25,26}have also been repor-

ted. More recently, we have described a wholly synthetic

*Corresponding author. Tel.: (617) 494-044 ext.275; Fax: (617)

494-1828; E-mail: dennis.holt@ariad.com

^yPresent address: Pharmacopeia, Inc., 101 College Road East,

Princeton, NJ 08540, USA.

PII: S0968-0896(98)00125-4

1310

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

Figure 2. Prototypical synthetic ligand used as basis for syn-

thetic CIDs.

Figure 1. FK1012, a chemical inducer of dimerization (CID).

A model synthetic dimerizer, 1a, having a 10-atom

bisamide linker, was prepared and tested in these assays

(Table 1). Compound 1a proved to be essentially inac-

tive in all three assays, showing only very weak induc-

tion of transcription in the transiently transfected cells

at high concentrations. The diaminoethyl portion of the

linker of 1a was replaced with a number of structurally

diverse diamines in an attempt to provide greater ¯exi-

bility between the monomeric units, but all compounds

were devoid of activity in these assays (compounds and

data not shown).

dimerizer, AP1510, derived from a simple non-macro-

cyclic FKBP12 ligand.¹⁰Despite having signi®cantly

weaker anity for FKBP12, AP1510 proved to be

comparable to FK1012 in activating Fas-mediated

apoptosis and substantially better than FK1012 in acti-

vating gene expression.

While small-molecule regulated protein dimerization

has already proven to be a versatile and general tool for

research and medical applications, its performance in

any particular context may be in¯uenced by the nature

of the CID employed. Apart from the traditional prop-

erties that aect drug ecacy, such as biological stabi-

lity, cell permeability, and pharmacokinetics, some

dimerization-initiated events appear to be especially

sensitive to the spatial orientation of the signaling fusion

proteins.^10,15Thus, CID selection from a collection of

compounds may be necessary for achieving optimal

ecacy. Herein, we report synthetic details and struc-

ture±activity studies for one extended family of AP1510

congeners.

The ®nding that 2a, the monomeric precursor of 1a,

exhibited a 240-fold lower anity for FKBP12 than

FK506 (Table 2), suggested that a tighter binding

monomer might be critical for dimerizer activity. A num-

ber of closely related monomers (2b±e) were prepared in

Results and Discussion

The X-ray crystal structure of a high-anity pipecolyl

a-ketoamide ligand in complex with FKBP12²⁹pro-

vided the basis for the original design of wholly syn-

thetic CIDs (Fig. 2). The solvent-exposed `eastern'

phenyl ring served as a convenient site for attachment of

a dimerizing linker moiety, while the `northwestern'

phenethyl appendage served as a readily-modi®able

stage for introducing additional hydrophilic or hydro-

phobic functionality. Thus, two series of symmetrical

homodimerizers were prepared in which the phenethyl

substituents and linker moieties were independently

varied. Dimerizers were tested in three previously

described assay systems; induction of Fas-mediated

apoptosis and induction of gene transcription in tran-

siently or stably transfected cells (Fig. 3).

Figure 3. Schemes for obtaining dimerizer-dependent (A)

apoptosis via Fas activation; and (B) regulation of gene

expression.

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1311

Table 1. In vitro cellular activities of synthetic dimerizers

Compd

R

L

Apoptosis IC₅₀(nM) Transcription EC₅₀(nM)^a/% expression^b

transient

stable

nc (1%)

1a (AP1932)

>1000

ꢀ500 (8%)

1b (AP1930)

ꢀ200

ꢀ250 (50%)

nc (2%)

1c (AP1933)

1d (AP1510)

1e (AP22375)

1f (AP1539)

1g (AP1909)

1h^c(AP22398)

ꢀ500

6

ꢀ500 (15%)

15 (100%)

nc (1%)

20 (100%)

ꢀ500 (23%)

nc (2%)

400

30

ꢀ300 (60%)

ꢀ400 (40%)

Nc (0%)

1000

60

nc (1%)

ꢀ300 (115%)

ꢀ300 (120%)

1i (AP1908)

1j (AP1428)

1k (AP1427)

20

10

15

20 (35%)

15 (75%)

10 (10%)

nc (3%)

8 (9%)

nc (3%)

1l (AP1980)

80

70 (65%)

ꢀ 150 (50%)

(continued)

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T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

Table 1Ðcontd

Compd

R

L

Apoptosis IC₅₀(nM) Transcription EC₅₀(nM)^a/% expression^b

transient

stable

1m (AP1981)

1n (AP3358)

1o (1871)

6

100

700

350

200

140

25

15 (115%)

25 (110%)

70 (50%)

ꢀ150 (100%)

ꢀ250 (85%)

ꢀ150 (60%)

80 (25%)

nc (2%)

ꢀ400 (53%)

ꢀ400 (60%)

nc (2%)

1p (AP1592)

1q (AP1511)

1r (AP1578)

1s (AP1979)

nc (5%)

15 (100%)

20 (120%)

^aEC₅₀s expressed as ꢀ indicate the dimerizer concentration giving half-maximal response when maximal response was observed at the

highest concentration tested (1mM); nc indicates no EC₅₀was calculable due to low expression levels.

^bPeak levels of protein expression normalized to peak expression of 1d (AP1510).

^cl-Proline analogue.

^dPara substituted linker attachment.

hopes of increasing anity for FKBP12 by increasing

the lipophilicity of the phenethyl appendage. In addi-

tion, the possibility that poor water solubility of 1a

might contribute to its inactivity led to the preparation

of pyridine- and morpholine-containing monomers 2f

and 2g, both of which were considered to have vastly

improved aqueous solubility compared to 2a. Of these

monomers, only the dimethoxy analogue, 2d, showed

slightly (threefold) enhanced FKBP12 binding while the

morpholino analogue, 2g, was about fourfold weaker

than 2a (Table 2).

nanomolar concentrations. The trimethoxyphenyl,

monomethoxyphenyl and pyridyl compounds, 1b, 1e and

1f, respectively, all showed weak activity in the transient

transcription assay, but with much higher EC50s and

expression levels that were only half that of 1d at the

highest concentration tested (1 mM). In the stable tran-

scription assay, 1e was the only compound of the initial

series other than 1d that displayed even weak activity.

Although the slightly greater FKBP12 anity of 2d was

commensurate with the superior cellular activity of its

dimer 1d, its anity was only threefold better than the

original model monomer 2a. Furthermore, pyridyl ana-

logue 2f which proved to be reasonably potent in the

Fas assay had equivalent FKBP12 anity to the Fas-

inactive analogs 1a and 1c. Even more striking, while 1f

was only ®vefold less potent than 1d in the Fas assay, it

was at least 25-fold weaker in the transient transcription

assay and all but devoid of activity in the stable tran-

scription assay.

A dimerizer series was constructed from the above

monomers (2b±g) in which the 10-atom bisamide linker

of 1a was held constant while the modi®cations to the

phenethyl substituent were examined (Table 1, 1a±g). In

this series only two dimerizers exhibited signi®cant

activity in the Fas assay, the dimethoxyphenyl ana-

logue 1d (AP1510) and the pyridyl analogue 1f. In both

transcription assays, only 1d showed activity at low

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1313

Table 2. Anities of FKBP12 monomeric ligands

of the six-membered ring pipecolyl core by the ®ve-

membered ring proline. This change was expected and

found to result in an approximate loss of FKBP12 a-

nity by one order of magnitude (monomer 2h, Table 2).

As this structural change is buried more deeply in the

FKBP12 binding pocket, it is less likely to result in

additional perturbations in the ternary complex. Con-

sistent with this notion, 1h showed a general loss in

activity in all assays, relative to 1d, that was of similar

magnitude as its loss in FKBP12 anity.

Compd

FK506

2a

R

IC₅₀(nM)

2.5

Rel. anity

0.004

A second series of dimerizers was examined in which the

dimethoxyphenyl-containing monomer 2d was held

constant and the length and chemical nature of the lin-

ker moiety was varied (Table 1, 1i±s). Compounds 1i, 1j,

and 1k retained the basic 1d bisamide linker although

with varying lengths. A modest threefold decrease in

ecacy for inducing apoptosis was observed for 1i,

relative to 1d, otherwise no dramatic change in activity

was seen for these compounds in the Fas assay. In con-

trast, none of the compounds showed any activity in the

stable transcription assay. Mixed results were observed

in the transient assay as only 1j had activity comparable

to 1d. Thus, it appears that CID ecacy in the Fas assay

is less sensitive to minor structural changes than are the

transcription assays.

600

1.0

2b

820

1.4

2c

2d

400

180

0.7

0.3

2e

910

1.5

Dierent bisamide con®gurations in linkers of 10, 9 and

®ve-atom lengths were installed in compounds 1l, 1m, and

1n. Compounds 1l and 1m share an ethoxyamino tether

that was coupled to form an oxamide and a urea,

respectively, and 1n was derived from anilino monomers

to yield a short `retro' bisamide linked dimerizer.

Despite the alteration in the arrangement of atoms of

the linker, both 1l and 1m proved to be eective in

inducing apoptosis as well as inducing transcriptional

activation in both transient and stable systems. In fact,

1m in all instances appeared to be slightly superior to

1d. The shortest dimerizer, 1n, proved to be only mod-

estly eective in inducing apoptosis and ineective at

inducing transcriptional activation in the stable cell line,

although, signi®cant activity was observed in the tran-

sient transcription assay. A more radically altered set of

compounds incorporating polyether linkers was also

examined (1o±r). This set spanned the range of linker

lengths from ®ve atoms (ꢁ7.3 A distance between aro-

matic rings) for 1o to seven atoms for 1p, 10-atoms for 1q,

and 13-atoms for 1r. In all cases, the ability to induce

apoptosis in the Fas assay was poor. A divergence of

activities was seen in the ability of these dimers to

induce transcriptional activation. In the transient tran-

scription assay, 1o, 1p, and 1q induced transcriptional

activation with potencies only 10- to 20-fold lower than

1d while the longer-linked compound 1r was able only

to achieve one-fourth the level of expression as 1d. The

greater ¯exibility of ®ve-atom linker of 1o relative to the

2f

650

2480

1460

1.1

4.1

2.4

2g

2h^a

^al-Proline analogue.

Apparently, subtle structural variation in the FKBP12-

binding region of the dimerizers can have profound

eects on their cellular potencies which are not necessa-

rily related to their FKBP12 anities. More recent

structural studies on a related series of synthetic dimer-

izers have revealed, in contrast to the observations for

FK1012,²⁸a close association of both of the bound

FKBP12 domains with each monomer unit of the

dimerizer, including parts of the phenethyl side chain.³⁰

Thus, alterations to this appendage which lead to dif-

ferences in the binding of monomers to a single

FKBP12 molecule may conceivably result in profoundly

dierent binding properties within the tripartite com-

plex. Relevant to this proposal, compound 1h was pre-

pared which is identical to 1d except for a replacement

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T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

®ve-atom bisamide linker of 1n may account for the dra-

matic dierence in activities of these two compounds.

condensation of an appropriate aromatic aldehyde with

a 3⁰- or 4⁰-hydroxyacetophenone. The product chalcones

were then regioselectively reduced via hydrogenation

with Lindlar catalyst to aord the 1,3-diphenylpropa-

nones 4b±f and 5. A `prelinker' tert-butylacetate unit

was then emplaced by alkylation of the resultant phe-

nols with tert-butyl bromoacetate. In the case of alcohol

9, the intermediate 4d was alkylated instead with N-

BOC-bromoethanamine.³¹Finally, the enantioselective

reduction of these O-alkylated propanones was achieved

using (+)-b-chlorodiisopinocamphenylborane ((+)-

DIP-Chloride²)³²to provide alcohols 6b±f, and 9 in 97±

98% enantiomeric excess. Alcohol 6a, was prepared by

regiospeci®c alkylation of the known (1R)-3-phenyl-(3-

hydroxyphenyl)-propan-1-ol (98% ee) with tert-butyl

bromoacetate.²⁹Alcohol 8 was prepared from the

Mannich base 7 by alkylation with tert-butyl bromo-

acetate followed by enantioselective reduction to aord 8

in 95% ee. Alcohol 11 was prepared from 3⁰-nitroaceto-

phenone in a similar manner to 6b±f, however, the

resulting aniline 10, rather than being alkylated with a

prelinker subunit, was protected as its BOC derivative

and reduced with (+)-DIP-Chloride²to aord the

desired alcohol in 98% ee. Due to the expected acid

instability of the 4⁰-alkoxy substituted carbinol deriva-

tive, we chose to exchange the tert-butyl ester protecting

Finally, a regioisomeric linker was examined with the

preparation of compound 1s wherein the linker was

attached to the para position of the phenyl ring as

opposed to the meta position as in 1d. Despite the geo-

metric change, 1s exhibited only fourfold weaker activ-

ity in the Fas assay and activity in both transcription

assays that was essentially identical to that of 1d.

Chemistry

Dimerizers 1a±s (Table 1) were prepared via two general

routes. Both routes began with the elaboration of a

homochiral benzylic carbinol (Scheme 1). In the ®rst

route, these carbinols were ®rst esteri®ed with the

known pipecolic acid derivative 14²⁹and then subse-

quently dimerized via two-to-one coupling with a sym-

metrical bifunctional linker (Scheme 2). In the second

route, the carbinol subunits were ®rst dimerized and

then coupled to the pipecolic acid moiety (Scheme 3).

The syntheses of the carbinol subunits 6b±f, 9, and 13

(Scheme 1) were achieved by the Claisen±Schmidt

Scheme 1. Reagents and conditions: (a) 3⁰-Hydroxyacetophenone or 4⁰-hydroxyacetophenone, KOH, H₂O/EtOH, 0 ^ꢂC; (b) 3⁰-hydroxy

acetophenone, piperidine, re¯ux; (c) H₂, Lindlar catalyst, MeOH; (d) tert-butyl bromoacetate, K₂CO₃, DMF, 0 ^ꢂC; (f) (+)-DIP-

Chloride², THF, 20 ^ꢂC; (g) BrCH₂CH₂NHBOC, NaI, K₂CO₃, DMF, 60 ^ꢂC; (h) TFA, CH₂Cl₂, 0 ^ꢂC; (i). TMSCH₂CH₂OH, DCC,

DMAP, CH₂Cl₂, 0 ^ꢂC; (j) i. 3⁰-nitroacetophenone, KOH, H₂O/EtOH, 0 ^ꢂC; ii. H₂, Lindlar catalyst, MeOH; (k) (BOC)₂O, DIEA,

CH₂Cl₂.

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1315

Scheme 2. Reagents and conditions: (a) DCC, DMAP, CH₂Cl₂, 0 ^ꢂC; (b) TFA, CH₂Cl₂, 0 ^ꢂC; (c) HCl, CH₂Cl₂, 0 ^ꢂC; (d) TBAF, DMF,

0 ^ꢂC; (e) i. N,N⁰-disuccinimidyl carbonate, pyridine, CH₃CN, 0 ^ꢂC; ii. diamine-2HCl, TEA, CH₃CN, 0 ^ꢂC; (f) diamine, DCC, DMAP,

CH₂Cl₂, 0 ^ꢂC; (g) CDI, TEA, CH₂Cl₂, 0 ^ꢂC; (h) oxalyl chloride, TEA, CH₂Cl₂, 0 ^ꢂC; (i) malonic acid, BOP, DIEA, CH₂Cl₂, 0 ^ꢂC.

group of 5 with a ¯uoride-cleavable trimethylsilylethyl

ester. Enantioselective reduction of this intermediate

then aorded alcohol 13 with a 98% ee.

dimerized by BOP coupling with malonic acid to form

the diamide 1n.

Dimerizers 1o±r and 1h were prepared via the DCC

coupling of acids 14 or 29 with diols 23±26 and 28

(Scheme 3). Diol 23 was prepared from the phenolic

propanone 4d by treatment with epibromohydrin fol-

lowed by TBDMS ether protection of the resulting car-

binol. The protected bis-propanone was enantio-

selectively reduced with (+)-DIP-Chloride²to aord

the desired diol in 97% diastereomeric excess. Diols

24±26 of 95% de were prepared in a similar manner

by treatment of 4d with the appropriate bis-iodoethyl

ether followed by enantioselective reduction. Coupling

of 23±26 with 14 aorded dimers 1o±r after HF depro-

tection of the silyl ether intermediate for 1o. The ®nal

diol, 28, was prepared by base hydrolysis of alcohol 6d

to aord acid 27. The acid 27 was recrystallized to

>99% ee. Single crystal X-ray analysis con®rmed the

expected absolute con®guration. Dimerization of 27

with ethylenediamine/PyBOP aorded diol 28 which

Coupling of alcohols 6a±f, 8, 9, 11, and 13 to pipecolyl

acid 14 (Scheme 2) aorded esters 15a±f, 16, 17, 19, and

21. Acidolysis of the tert-butyl ester protecting groups

of 15a±f and 16 aorded the corresponding acids 2a±f

and 2g, while tetrabutylammonium ¯uoride treatment

of 21 removed the trimethylsilylethyl protecting group

to provide acid 22. The removal of BOC protecting

group of 17 and 19 aorded the corresponding amines

18 and 20. Dimerization of the monomeric acids 2a±g

and 22 with ethylenediamine via either the correspond-

ing succinimidyl esters or by DCC coupling aorded the

desired dimerizers 1a±g and 1s, whereas dimerization of

2d with 1,3-diaminopropane, 2,2⁰-oxybis(ethylamine),

and 2,2⁰-(ethylenedioxy)bis(ethyl amine) aorded

dimers 1i±k. Dimerization of 18 with either 1,1⁰-carbonyl-

diimidazole or oxalyl chloride aorded urea 1l and

oxamide 1m, respectively. Finally, the aniline 20 was

1316

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

Scheme 3. Reagents and conditions: (a) i. epibromohydrin, KOt-Bu, DMF, 100 ^ꢂC; ii. TBDMS-Cl, imidazole, DMF, 0 ^ꢂC; (b) (+)-

DIP-Chloride², THF, 20 ^ꢂC; (c) 2 equiv 14, DCC, DMAP, CH₂Cl₂, 0 ^ꢂC; (d) 49% HF, CH₃CN. (e) diiodide, NaH, DMF; (f) 6 N

NaOH, MeOH; (g) ethylenediamine, PyBOP, THF, TEA, 0 ^ꢂC; (h) DCC, DMAP, CH₂Cl₂, 0 ^ꢂC; (i) TFA, CH₂Cl₂, 0 ^ꢂC.

was then coupled to either acid 14 or 29 to aord

dimers 1d and 1h, respectively. The monomeric acid

2h was prepared for binding studies by DCC coupling

of acid 29 and alcohol 6d followed by acidolysis

deprotection.

spatial orientations of the two binding sites, dierences

in potentials for hydrophobic collapse, or dierences in

entropic costs for binding. Multiple FKBP12 domains

may result in complexes stabilized by avidity eects, and

these eects may be more or less sensitive to dimerizer

structural changes than is single FKBP12 anity. The

observation that some CIDs behave as `partial agonists'

in the transcription assay, having sub-maximal plateau

expression levels, suggests that some compounds may

produce a signi®cant population of signalling-incompe-

tent complexes. Similarly, on- and o-rates may play a

role in multi-receptor dimerization where remodeling of

initially-formed, non-productive protein conformations

might be required to achieve the biological response. In

support of this supposition is the observation that some

compounds of very poor ecacy in stably transfected

cells show much greater potency in transiently trans-

fected cellsÐpresumably compensated by the higher

target protein concentrations in the latter. Possible

dierences in cellular permeability or partitioning could

also account for some variation in compound ecacies.

Conclusions

AP1510 (1d) has previously been shown to be a versatile

synthetic CID for regulating intracellular protein±pro-

tein interactions.¹⁰In this report we have detailed syn-

thetic routes to an extended family of AP1510 congeners

and examined the activities of these dimerizers in two

types of cell-based assays; induction of Fas-mediated

apoptosis and activation of gene expression. The dimer-

izers of this study dier structurally from AP1510 at one

of two sites. Variations to the length and character of the

linker were examined as were variations within the phe-

nethyl side chain portion of the FKBP12 binding domain.

While clear structure±activity relationships are as yet

dicult to precisely de®ne, it is apparent that FKBP12

anity is not the only determining factor and that CID

ecacy is application-dependent and sensitive to even

modest molecular changes. These subtle structural var-

iations presumably lead to dierences in the relative

The ability to readily modify the wholly-synthetic

AP1510 family of CIDs should facilitate application-

dependent compound optimizations and better our

understanding of the geometric and kinetic factors

which in¯uence CID activity.

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1317

Experimental

(1.3 mL, 8.8 mmol) and allowed to stir at room tem-

perature for 20 h. After this time the reaction mixture

was ®ltered, concentrated, and ¯ash chromatographed

to aord product.

General methods. All reagents and solvents were

obtained from commercial sources and used without

further puri®cation. All melting points were measured

on a Laboratory Devices MEL-TEMP II apparatus and

are uncorrected. All IR spectra were recorded on a Per-

kin-Elmer 1600 Series FTIR and ¹H, ¹⁹F, and ¹³C NMR

spectra on a Bruker ARX-300 instrument. Chemical

shifts are reported down®eld from tetramethylsilane and

in cases where a mixture of keto-amide rotamers is pre-

sent, only the chemical shifts of the major rotamer are

reported. Low resolution mass spectra (LRMS) were

obtained on a Micromass Platform II quadrupole mass

spectrometer operating in electrospray mode while high

resolution mass spectra (HRMS) were obtained on a

JEOL SX-102A mass spectrometer using fast atom

bombardment (FAB). Data for HRMS were recorded at

a mass resolution of 10,000 and internally calibrated

using reference ions from poly(ethylene glycol) or

poly(propylene glycol) as appropriate. Flash chroma-

tography was performed on silica gel (Merck, 230±

400 mesh). Analytical TLC was performed on silica

gel 60 F₂₅₄plates (Merck). Chiral HPLC was per-

formed on Chiral Technologies Inc. (Exton, PA)

analytical columns.

General procedure D. A 60% mineral oil suspension of

NaH (4.2 g, 105 mmol) in anhydrous DMF (125 mL)

was cooled to 5 ^ꢂC in an ice bath and phenol 2

(90 mmol) was added portionwise. The resulting yellow

solution was stirred for 15 min followed by addition of

tert-butyl bromoacetate (16.2 mL, 110 mmol). The

reaction mixture was stirred at 5 ^ꢂC for 15 min,

allowed to warm to room temperature, and parti-

tioned between EtOAc (200 mL) and water (200 mL).

The organic phase was washed with brine (4Â200 mL),

dried over Na₂SO₄, ®ltered, and concentrated to

aord crude product which was puri®ed by ¯ash

chromatography.

General procedure E. A solution of ketone (90 mmol) in

THF (50 mL) at 20 ^ꢂC was treated with a solution of

(+)-DIP-Chloride²(43.3 g, 135 mmol) in THF (100 mL)

at 20 ^ꢂC. The resulting mixture was allowed to stand in

a

10 ^ꢂC freezer for 16 h after which time the mixture

was concentrated and treated with diethyl ether

(300 mL) followed by diethanolamine (77.6 mL,

810 mmol). The viscous mixture was allowed to stir at

room temperature for 6 h after which time it was ®ltered

through a pad of Celite with the aid of EtOAc. The ®l-

trate was concentrated and the crude material ¯ash

chromatographed to aord product.

General procedure A.

A solution of aldehyde 3

(600 mmol) and acetophenone (600 mmol) in EtOH

(200 mL) was cooled to 0 ^ꢂC and treated with a cold

(ꢁ10 ^ꢂC) solution of aqueous KOH (1 L, 2400 mmol).

The resulting solution was allowed to warm to room

temperature and stir for 16 h at room temperature. The

resulting slurry was then poured onto ice (1 L) contain-

ing 12 N HCl (200 mL) resulting in a yellowish pre-

cipitate. The aqueous portion was decanted and the

solids triturated with water (4Â500 mL) then dissolved

in EtOAc (1 L). The organic extract was washed with

brine (2Â200 mL), dried over Na₂SO₄, ®ltered, and

concentrated to aord chalcone product.

General procedure F. A solution of alcohol (1.0 mmol),

carboxylic acid (1.1 mmol), and DMAP (0.11 mmol) in

CH₂Cl₂(1.0 mL) at 0 ^ꢂC was treated with DCC

(1.1 mmol). The mixture was allowed to warm to room

temperature and stir for 2 h after which time it was

diluted with EtOAc (4 mL) and ®ltered through a plug

of Celite. The ®ltrate was concentrated and the crude

material ¯ash chromatographed to aord product.

General procedure B. A solution of chalcone (90 mmol)

and Lindlar catalyst (5% Pd, 2.5 g) in MeOH (100 mL)

was hydrogenated at 40±50 psi pressure of H₂in a Parr

hydrogenator for 6 h. The reaction mixture was then

®ltered and the ®ltered solids dissolved in hot MeOH

(400 mL). The methanolic solution was ®ltered while hot

and the combined ®ltrates cooled and re®ltered through

a pad of Celite to remove small amounts of remaining

catalyst. The ®ltrate was concentrated to a solid and ®l-

tered with the aid of EtOAc (100 mL) or otherwise

indicated solvent.

General procedure G. A solution of tert-butyl ester

(0.4 mmol), in CH₂Cl₂(6.0 mL) at 0 ^ꢂC was treated with

TFA (2.0 mL). The mixture was allowed to warm to

room temperature and stir for 2 h after which time it

was diluted with benzene (25 mL) and concentrated. The

crude material was then ¯ash chromatographed to

aord product.

General procedure H.

A

solution of substrate

(0.4 mmol), in CH₂Cl₂(20.0 mL) at 0 ^ꢂC was purged

with a slow stream of hydrogen chloride for 5 min. The

mixture was allowed to warm to room temperature and

stir for 2 h after which time it was diluted with benzene

(25 mL) and concentrated. The crude material was then

¯ash chromatographed to aord product.

General procedure C.

(8.0 mmol) and K₂CO₃(2.21 g, 16.0 mmol) in acetone

A

solution of phenol

4

(25 mL) was treated with tert-butyl bromoacetate

1318

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

General procedure I. A solution of carboxylic acid

(0.70 mmol) in CH₂Cl₂(1.5 mL) at 0 ^ꢂC was treated with

DCC (148 mg, 0.70 mmol) followed by DMAP (8.6 mg,

0.07 mmol). The suspension was allowed to stir for

5 min after which time a solution of CH₂Cl₂(100 mL)

containing ethylenediamine (18.7 uL, 0.28 mmol) was

added. The reaction was allowed to warm to room

temperature and stir for 5 h, after which time it was

diluted with EtOAc (5 mL), ®ltered through a plug of

glass wool, concentrated, and ¯ash chromatographed to

aord product.

stirred for 15 min followed by addition of the bis-

iodoethyl ether (14 mmol). The reaction mixture was

allowed to warm to room temperature and stir for 16 h

then partitioned between EtOAc (200 mL) and water

(250 mL). The organic phase was washed with brine

(3Â200 mL), dried over Na₂SO₄, ®ltered, and con-

centrated to aord crude product which was puri®ed by

¯ash chromatography.

1-(3-Hydroxyphenyl)-3-(3,4,5-trimethoxyphenyl)-1-prop-

anone (4b). General procedure A was used for the reac-

tion of 3,4,5-trimethoxybenzaldehyde and 3⁰-hydroxy-

acetophenone. The crude solids were treated with

EtOAc (50 mL) followed by hexane (50 mL) then ®ltered

to aord product (9.22 g, 59%) as a yellow solid: mp

173±174 ^ꢂC; TLC (EtOAc/hexane, 2/3) R_f=0.25; ¹H

NMR (CDCl₃, 300 MHz) 9.80 (s, 1H), 7.82 (d,

J=15.6 Hz, 1H), 7.70±7.63 (m, 2H), 7.48 (s, 1H), 7.39 (t,

J=7.9 Hz, 1H) 7.23 (s, 2H) 7.08 (d, J=7.6 Hz, 1H), 3.87

(s, 6H), 3.73 (s, 3H); ¹³C NMR (CDCl₃, 75 MHz) 189.5,

158.1, 153.5, 144.7, 140.1, 139.5, 130.6, 130.1, 121.8,

120.5, 119.9, 115.0, 106.9, 60.5, 56.5. LRMS (ES+):

(M+H)⁺315.

General procedure J. A solution of carboxylic acid

(2.90 mmol) in CH₃CN (30 mL) was treated with di-

succinimidyl carbonate (1.12 g, 4.37 mmol) followed by

pyridine (704 mL, 8.70 mmol) and allowed to stir for

24 h. The reaction mixture was diluted with EtOAc

(200 mL), washed with brine (2Â200 mL), dried over

Na₂SO₄, ®ltered, concentrated, and ¯ash chromato-

graphed (75% EtOAc/hexane) to aord crude product.

A

solution of the semi-pure succinimidyl ester

(2.50 mmol) in CH₃CN (25 mL) was treated with either

ethylenediamine dihydrochloride (150 mg, 1.125 mmol)

or ethylenediamine (75.2 mL, 1.125 mmol) followed by

triethylamine (1.74 mL, 12.5 mmol or 349 mL, 2.5 mmol)

and allowed to stir for 4 h. The reaction mixture was

then diluted with EtOAc (200 mL), washed with brine

(2Â100 mL), dried over Na₂SO₄, ®ltered, concentrated,

and ¯ash chromatographed to aord product.

General procedure B was used for the reduction of the

above chalcone. Solids were chromatographed (40%

then 50% EtOAc/hexane) to aord product (1.37 g,

68%) as a colorless solid: mp 138±139 ^ꢂC; TLC (EtOAc/

hexane, 2:3) R_f=0.28; IR (neat) 3395, 2940, 1680, 1590,

1

1505, 1455, 1240, 1125 cm

;

¹H NMR (CDCl₃,

General procedure K. A solution of diol (0.40 mmol),

acid (1.00 mmol), and DMAP (12 mg, 0.10 mmol) in

CH₂Cl₂(1.0 mL) at 0 ^ꢂC was treated with DCC (206 mg,

1.00 mmol). The mixture was allowed to warm to room

temperature and stir for 2 h after which time it was

diluted with EtOAc (4 mL) and ®ltered through a plug

of Celite. The ®ltrate was concentrated and the crude

material ¯ash chromatographed to aord product.

300 MHz) 7.54±7.52 (m, 2H), 7.34 (app t, J=8.1 Hz,

1H), 7.10 (dd, J=7.9, 2.2 Hz, 1H), 6.48 (s, 2H), 6.08 (s,

1H), 3.85 (s, 9H), 3.30 (t, J=7.3 Hz, 2H), 3.02 (t,

J=7.7 Hz, 2H); ¹³C NMR (CDCl₃, 75 MHz) 200.0,

156.7, 153.6, 138.7, 137.4, 136.7, 130.3, 120.9, 115.0,

105.8, 61.3, 56.5, 41.0, 31.0; LRMS (CI+): (M+H)⁺

317, (M+NH₄)⁺334.

3-(1,3-Benzodioxol-5-yl)-1-(3-hydroxyphenyl)-1-propanone

(4c). General procedure A was used for the reaction of

3,4-(methylenedioxy)benzaldehyde and 3⁰-hydroxy-

acetophenone. The crude solids were ®ltered with the

aid of EtOAc (50 mL) to aord 7.0 g of yellow solids.

The solids were recrystallized from EtOAc to aord

product (4.6 g, 34%) as a yellow solid: mp 184±185 ^ꢂC;

TLC (EtOAc/hexane, 3/7) R_f=0.26; ¹H NMR

(CD₃OD, 300 MHz) 7.60 (d, J=15.6 Hz, 1 H), 7.44±7.42

(m, 2 H), 7.32 (s, 1 H), 7.27±7.12 (m, 2 H), 7.10 (d,

J=6.5 Hz, 1 H), 6.94 (dd, J=8.1, 2.5 Hz, 1 H), 6.78 (d,

J=8.0 Hz, 1 H), 5.92 (s, 2 H); ¹³C NMR (CD₃OD,

75 MHz) 192.8, 159.5, 152.0, 150.4, 146.6, 131.2, 127.1,

121.6, 121.3, 116.2, 110.0, 108.2, 105.7, 103.5; LRMS

(ES+): (M+H)⁺269, (M+NH₄)⁺286.

General procedure L.

A solution the bis-ketone

(1.0 mmol) in THF (10 mL) at 20 ^ꢂC was treated with a

solution of (+)-DIP-Chloride²(1.28 g, 4.0 mmol) in

THF (15 mL) at 20 ^ꢂC. The resulting mixture was

allowed to stand in a 10 ^ꢂC freezer for 16 h after which

time the mixture was concentrated and treated with

diethyl ether (30 mL) followed by diethanolamine

(2.3 mL, 24 mmol). The viscous mixture was allowed to

stir at room temperature for 6 h after which time it was

®ltered through a pad of Celite with the aid of EtOAc.

The ®ltrate was concentrated and the crude material

¯ash chromatographed to aord product.

General procedure M. A 60% mineral oil suspension of

NaH (1.4 g, 35.0 mmol) in anhydrous DMF (25 mL) was

cooled to 5 ^ꢂC in an ice bath and 4d (10 g, 35 mmol)

added portionwise. The resulting yellow solution was

General procedure B was used for the reduction of the

above chalcone. Recrystallization of solids from

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1319

1

EtOAc/hexane aorded product (4.10 g, 41%) as a color-

less solid: TLC (EtOAc/hexane, 3/7) R_f=0.40; mp

1245, 1175 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.53±

7.48 (m, 2 H), 7.31 (t, J=7.9 Hz, 1 H), 7.13 (d,

J=8.4 Hz, 1 H), 7.07 (dd, J=7.9, 1.7 Hz, 1 H), 6.82 (d,

J=8.5 Hz, 1 H), 6.23 (s, 1 H), 3.77 (s, 3 H), 3.24 (t,

J=7.2 Hz, 2 H), 2.99 (t, J=7.7 Hz, 2 H); ¹³C NMR

(CDCl₃, 75 MHz) 200.2, 158.0, 156.4, 138.2, 133.2,

129.9, 129.4, 120.7, 114.6, 114.0, 55.3, 40.8, 29.4; LRMS

(ES+): (M+H)⁺257; (ES ): (M H) 255.

146±147 ^ꢂC; H NMR (CDCl₃, 300 MHz) 9.73 (s, 1H),

1

7.43 (d, J=7.8 Hz, 1H), 7.34±7.29 (m, 2H), 7.02 (d,

J=8.0 Hz, 1H), 6.88 (m, 1H), 6.80 (d, J=7.9 Hz, 1H),

6.71 (d, J=7.9 Hz, 1H), 5.96 (s, 2H), 3.26 (t, J=7.6 Hz,

2H), 2.84 (t, J=7.5 Hz, 2H); ¹³C NMR (CDCl₃,

75 MHz) 199.4 158.0, 147.5, 145.7, 138.4, 135.4, 130.1,

121.5, 120.5, 119.3, 114.4, 109.2, 108.4, 101.0, 40.2, 29.7;

LRMS (ES ): (M H) 269.

1-(3-Hydroxyphenyl)-3-(3-pyridinyl)-1-propanone (4f). A

mixture of 3⁰-hydroxyacetophenone (5.0 g, 36.7 mmol),

3-pyridinecarboxaldehyde (3.93 g, 36.7 mmol), and

piperdine (7.26 mL, 73.4 mL) in EtOH (30 mL) was

heated at re¯ux for 48 h. After this time the reaction

mixture was concentrated and the residue ¯ash chro-

matographed (5% then 10% MeOH/CH₂Cl₂) to aord

crude product which was triturated with a 40% EtOAc/

hexane solution to aord chalcone product (3.44 g,

33%) as a solid: TLC (MeOH/CHCl₃, 5/95) R_f=0.32;

¹H NMR (DMSO-d₆, 300 MHz) 9.78 (s, 1 H), 9.01 (s, 1

H), 8.61 (d, J=3.9 Hz, 1 H), 8.35 (d, J=8.0 Hz, 1 H),

7.99 (d, J=15.8 Hz, 1 H), 7.74 (d, J=15.8 Hz, 1 H), 7.65

(d, J=7.7 Hz, 1 H), 7.51±7.47 (m, 2 H), 7.38 (t,

J=7.9 Hz, 1 H), 7.08 (dd, J=8.0, 2.3 Hz, 1 H); ¹³C

NMR (DMSO-d₆, 75 MHz) 189.3, 158.1, 151.3, 150.7,

140.7, 139.0, 135.4, 131.0, 130.2, 124.5, 124.3, 120.9,

120.1, 115.1; LRMS (ES+): (M+H)⁺226, (ES ):

(M H) 224.

3-(3,4-Dimethoxyphenyl)-1-(3-hydroxyphenyl)-1-propanone

(4d). General procedure A was used for the reaction

of 3,4-dimethoxybenzaldehyde and 3⁰-hydroxyaceto-

phenone. Filtration aorded product (155 g, 91%) as a

yellow colored solid: mp 138±139 ^ꢂC; TLC (EtOAc/hex-

ane, 1/1) R_f=0.35; ¹H NMR (DMSO-d₆, 300 MHz) 9.85

(br s, 1H), 7.71 (d, J=6.6 Hz, 2H), 7.61 (d, J=7.7 Hz,

1H), 7.53 (d, J=1.7 Hz, 1H), 7.47 (d, J=1.7 Hz, 1H),

7.39±7.34 (m, 2H), 7.07±7.00 (m, 2H), 3.87 (s, 3H), 3.82

(s, 3H); ¹³C NMR (DMSO-d₆, 75 MHz) 189.4, 158.2,

151.6, 149.4, 144.7, 139.7, 130.1, 127.9, 124.2, 120.4,

120.2, 119.7, 115.0, 112.0, 111.2, 56.1, 56.0; LRMS

(ES+) (M+H)⁺285.

General procedure B was used for the reduction of the

above chalcone. Recrystallization from EtOAc aorded

product (19.1 g, 76%) as a colorless solid: mp 132±

134 ^ꢂC; TLC (EtOAc/hexane, 1/1) R_f=0.42; ¹H NMR

(DMSO-d₆, 300 MHz) 9.73 (s, 1H), 7.43 (d, J=7.8 Hz,

1H), 7.33±7.28 (m, 2H), 7.02 (dd, J=8.0, 1.9 Hz, 1H),

6.88±6.74 (m, 3H), 3.73 (s, 3H), 3.70 (s, 3H), 3.20 (t,

J=7.4 Hz, 2H), 2.86 (t, J=7.5 Hz, 2H); ¹³C NMR

(DMSO-d₆, 75 MHz) 199.6, 158.0, 149.0, 147.5, 138.5,

134.1, 130.1, 120.5, 119.3, 114.5, 112.9, 112.3, 55.9, 55.8,

40.2, 29.6; LRMS (ES+) (M+NH₄)⁺304.

A mixture of the above chalcone (9.0 g, 40.0 mmol) and

Lindlar catalyst (5% Pd, 2.25 g) in MeOH (225 mL) was

hydrogenated in a Parr hydrogenator under H₂at 40 psi

for 16 h. The mixture was ®ltered through Celite and the

®ltrate concentrated to aord a residue which was

chromatographed (50% then 60% EtOAc/hexane) to

aord product (4.5 g, 50%) as a colorless oil: TLC

(MeOH/CHCl₂, 5/95) R_f=0.29; IR (neat) 2930, 1680,

1

1-(3-Hydroxyphenyl)-3-(4-methoxyphenyl)-1-propanone

(4e). General procedure A was used for the reaction of

4-methoxybenzaldehyde and 3⁰-hydroxyacetophenone.

Filtration aorded product (83 g, 88%) as a yellow

solid: TLC (EtOAc/hexane, 2/3) R_f=0.40; IR (neat)

1585, 1450, 1295, 1175 cm

;

¹H NMR (DMSO-d₆,

300 MHz) 9.73 (s, 1 H), 8.50 (s, 1 H), 8.39 (d, J=4.2 Hz,

1 H), 7.71 (d, J=7.8 Hz, 1 H), 7.42 (d, J=7.6 Hz, 1 H),

7.32±7.27 (m, 3 H), 7.00 (dd J=8.0, 2.3 Hz, 1 H), 3.35±

3.32 (obs m, 2 H), 2.93 (t, J=7.3 Hz, 2 H); ¹³C NMR

(DMSO-d₆, 75 MHz) 199.1, 158.0, 149.9, 147.3, 138.3,

137.0, 136.5, 130.1, 123.8, 120.6, 119.3, 114.4, 39.4, 27.0;

LRMS (ES+): (M+H)⁺228.

1

3360, 1565, 1510, 1255, 1170 cm ¹; H NMR (DMSO-

d₆, 300 MHz) 9.84 (s, 1 H), 7.90 (d, J=8.7 Hz, 2 H), 7.77

(s, 2 H), 7.68 (d, J=7.6 Hz, 1 H), 7.54 (s, 1 H), 7.44 (d,

J=7.9 Hz, 1 H), 7.13 (dd, J=8.1, 2.3 Hz, 1 H), 3.88 (s, 3

H); ¹³C NMR (DMSO-d₆, 75 MHz) 189.4, 161.7, 158.1,

144.2, 139.7, 131.1, 130.1, 127.7, 120.4, 120.1, 119.8,

115.0, 114.8, 55.7; LRMS (ES+): (M+H)⁺255; (ES ):

(M H) 253.

3-(3,4-Dimethoxyphenyl)-1-(4-hydroxyphenyl)-1-propanone

(5). General procedure A was used for the reaction

of 3,4-dimethoxybenzaldehyde and 4⁰-hydroxyaceto-

phenone. Filtration aorded product (36.5 g, 64%) as a

yellow colored solid: mp 201±203 ^ꢂC; TLC (EtOAc/hex-

ane, 2/3) R_f=0.28; ¹H NMR (DMSO-d₆, 300 MHz)

10.34 (s, 1H), 8.07 (d, J=8.6 Hz, 2H), 7.79 (d,

J=15.5 Hz, 1H), 7.63 (d, J=15.5 Hz, 1 H), 7.51 (s, 1 H),

7.35 (dd, J=13.8, 8.3 Hz, 1 H), 7.01 (d, J=8.3 Hz, 1 H),

6.90 (d, J=8.6 Hz, 2 H), 3.86 (s, 3 H), 3.81 (s, 3 H); ¹³C

General procedure B was used for the reduction of the

above chalcone. Solids were chromatographed (40%

EtOAc/hexane) to aord product (23.4 g, 46%) as a

colorless solid: mp 91.5±92 ^ꢂC; TLC (EtOAc/hexane, 2/

3) R_f=0.50; IR (neat) 3415, 1665, 1595, 1510, 1450,

1320

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

NMR (DMSO-d₆, 75 MHz) 187.0, 162.0, 151.0, 149.0,

143.1, 131.0, 129.3, 127.7, 123.6, 119.7, 115.3, 111.6,

110.6, 55.7, 55.6; LRMS (ES+): (M+H)⁺285; (ES ):

(M H) 283.

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(50% then 100% EtOAc/hexane) to aord product

(1.3 g, 99%) as a colorless oil (98% ee by Chiralcel OD

HPLC, 20% i-PrOH/hexane, retention time 46.4 min for

the R-enantiomer and 40.0 min for the S-enantiomer):

General procedure B was used for the reduction of the

above chalcone. Obtained product (500 mg, 50%) as a

colorless solid: mp 140±141 ^ꢂC; TLC (EtOAc/hexane, 2/

3) R_f=0.31; ¹H NMR (CDCl₃, 300 MHz) 7.89 (d,

J=8.7 Hz, 2 H), 6.92±6.77 (m, 6 H), 3.84 (m, 6 H), 3.24

(d, J=7.2 Hz, 2 H), 3.00 (t, J=7.3 Hz, 2 H); ¹³C NMR

(CDCl₃, 75 MHz) 199.3, 161.2, 149.3, 147.8, 134.4,

131.2, 130.1, 120.7, 115.9, 112.4, 111.9, 56.4, 56.3, 40.7,

30.6; LRMS (ES+): (M H) 285.

TLC (EtOAc/hexane, 2/3) R_f=0.26; IR (neat) 3500,

1

2940, 1750, 1590, 1455, 1240, 1150, 1130 cm

;

¹H

NMR (CDCl₃, 300 MHz) 7.28 (t, J=7.8 Hz, 1 H), 6.96

(m, 2 H), 6.82 (m, 1 H), 6.41 (s, 2 H), 4.69 (t, J=6.2 Hz,

1 H), 4.52 (s, 2 H), 3.85 (s, 6 H), 3.83 (s, 3 H), 2.65 (m, 2

H), 2.05 (m, 2 H), 1.50 (s, 9 H); ¹³C NMR (CDCl₃,

75 MHz) 168.4, 158.6, 153.5, 146.8, 137.9, 136.6, 130.0,

119.5, 114.0, 112.7, 105.7, 82.8, 74.1, 66.0, 61.2, 56.5,

40.8, 32.8, 28.4; LRMS (ES+): (M+NH4)⁺450;

HRMS (FAB): (M+Na)⁺calcd: 455.2046, recorded:

455.2063.

(R)-1,1-Dimethylethyl [3-(1-hydroxy-3-phenylpropyl)-

phenoxy]acetate (6a). (1R)-3-Phenyl-1-(3-hydroxyphenyl)-

propan-1-ol (98% ee, 1.7g, 7.46 mmol) was added to

a suspension of NaH (60% dispersion in mineral oil,

358 mg, 8.95mmol) in DMF (50 mL) and treated with

tert-butyl bromoacetate (2.4 mL, 14.9 mmol). The

resulting mixture was stirred at 40 ^ꢂC for 16 h then

quenched with water (50 mL) and extracted with EtOAc

(250 mL). The organic layer was washed with brine

(2Â100 mL), dried over Na₂SO₄, ®ltered, and con-

centrated to an oil residue. Chromatography (20%

EtOAc/hexane) aorded product (1.64 g, 64%) as a

colorless oil (98% ee by Chiralcel OD HPLC, 25%

i-PrOH/hexane, retention time 42.2 min for the R-

enantiomer and 30.6 min for the S-enantiomer): TLC

(R)-1,1-Dimethylethyl [3-[3-(1,3-benzodioxol-5-yl)-1-

hydroxypropyl]-phenoxy]acetate (6c). General procedure

D was used for the alkylation of 4c. The crude product

was chromatographed (20% then 30% EtOAc/hexane)

to aord product (5.04 g, 89%) as a waxy solid: mp 61±

62 ^ꢂC; IR (neat) 2980, 1750, 1685, 1490, 1445, 1245,

1155, 1040 cm ¹; ¹H NMR (CDCl₃, 300 MHz) 7.58 (dd,

J=6.7, 1.1 Hz, 1H), 7.48 (s, 1H), 7.39 (t, J=8.0 Hz, 1H),

7.17±7.13 (m, 1H), 6.89±6.69 (m, 4H), 5.94 (s, 2H), 4.58

(s, 2H), 3.25 (t, J=7.8 Hz, 2H), 2.99 (t, J=7.8 Hz, 2H),

1.51 (s, 9H); ¹³C NMR (CDCl₃, 75 MHz) 199.0 168.0,

158.5, 148.1, 146.3, 138.6, 135.4, 130.1, 121.8, 121.5,

120.6, 113.4, 109.3, 108.7, 101.2, 83.0, 66.1, 41.1, 20.3,

28.4; LRMS (ES+): (M+NH₄)⁺402.

(EtOAc/hexane, 1/4) R_f=0.26; IR (neat) 3520, 2930,

1

1745, 1600, 1490, 1455, 1370, 1230, 1150, 1085 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.22±6.71 (m, 9 H), 4.58

(t, 1 H), 4.44 (s, 2 H), 2.68±2.59 (m, 2 H), 2.05-1.93

(m, 2 H), 1.41 (s, 9 H); ¹³C NMR (CDCl₃, 75 MHz)

168.4, 158.6, 146.8, 142.1, 130.0, 128.8, 128.7, 126.2,

119.5, 114.1, 112.6, 82.7, 74.1, 66.1, 40.8, 32.4, 28.4;

HRMS (FAB): (M+Na)⁺calcd: 365.1729, recorded:

365.1721.

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(20% then 25% EtOAc/hexane) to aord product

(3.84 g, 96%) as a colorless oil (94% ee by Chiralcel OD

HPLC, 35% i-PrOH/hexane, retention time 11.3 min for

the R-enantiomer and 8.7 min for the S-enantiomer):

TLC (EtOAc/hexane, 3/7) R_f=0.31; IR (neat) 3440,

1

(R)-1,1-Dimethylethyl [3-[1-hydroxy-3-(3,4,5-trimethoxy-

phenyl)propyl]-phenoxy]acetate (6b). General procedure

C was used for the alkylation of 4b. The crude product

was chromatographed (50% EtOAc/hexane) to aord

product (3.30 g, 96%) as a colorless solid that may be

recystallized from EtOAc: mp 99±100 ^ꢂC; TLC (EtOAc/

1750, 1490, 1440, 1245, 1150, 1040 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.30±7.24 (m, 1 H), 6.98±6.93 (m,

2H), 6.82 (dd, J=8.2, 2.5 Hz, 1H), 6.75±6.64 (m, 3H),

5.93 (s, 2H), 4.67±4.63 (m, 1H), 4.53 (s, 2H), 2.68±2.60

(m, 2H), 2.10±1.95 (m, 3H), 1.51 (s, 9H); ¹³C NMR

(CDCl₃, 75 MHz) 168.4, 158.5, 148.0, 146.9, 146.0,

136.0, 130.0, 121.5, 119.5, 114.1, 112.5, 109.3, 108.5,

101.1, 82.7, 73.9, 66.1, 41.1, 32.1, 28.4; LRMS (ES+):

(M+NH₄)⁺404, (M+Na)⁺409; HRMS (FAB):

(M+)⁺calcd: 386.1728, measured: 386.1716.

hexane, 2/3) R_f=0.47; IR (neat) 2955, 1750, 1684, 1590,

1

1455, 1230, 1150, 1125 cm

;

¹H NMR (CDCl₃,

300 MHz) 7.59 (d, J=7.7 Hz, 1H), 7.49 (s, 1H), 7.39

(t, J=7.9 Hz, 1H), 7.14 (dd, J=8.2, 2.6 Hz, 1H), 6.47

(s, 2H), 4.58 (s, 2H), 3.86 (s, 6H), 3.84 (s, 3H), 3.28

(t, J=7.3 Hz, 2H), 3.01 (t, J=7.8 Hz, 2H), 1.50 (s, 9H);

¹³C NMR (CDCl₃, 75 MHz) 199.1 168.0, 158.5, 153.6,

138.6, 137.4 136.8, 130.1, 121.8, 120.4, 113.6, 105.8,

83.0, 66.1, 61.2, 56.5, 41.0, 31.0, 28.4; LRMS (ES+):

(M+NH4)⁺448, (M+Na)⁺453.

(R)-1,1-Dimethylethyl [3-[3-(3,4-dimethoxyphenyl)-1-

hydroxypropyl]phenoxy]-acetate (6d). General procedure

C was used for the alkylation of 4d. The crude product

was chromatographed (30% EtOAc/hexane) to aord

product (34.5 g, 99%) as a waxy solid: mp 56±56.5 ^ꢂC;

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1321

TLC (EtOAc/hexane, 1/1) R_f=0.65; IR (neat) 2975,

1750, 1685, 1590, 1515, 1445, 1370, 1260, 1235, 1155,

2H), 3.77 (s, 3H), 2.68±2.59 (m, 3H), 2.07±1.94 (m, 2H),

1.48 (s, 9H); ¹³C NMR (CDCl₃, 75 MHz) 168.0, 158.2,

157.8, 146.5, 133.8, 129.5, 129.3, 119.1, 113.9, 113.7,

112.2, 82.3, 73.6, 65.7, 55.3, 40.7, 31.1, 28.0; LRMS

(ES+): (M+NH₄)⁺390; HRMS (FAB): (M)⁺calcd:

372.1937, recorded: 372.1949.

1

1080, 1030 cm ¹; H NMR (CDCl₃, 300 MHz) 7.57 (d,

J=7.7 Hz, 1H), 7.47 (d, J=2.3 Hz, 1H), 7.39 (t,

J=8.0 Hz, 1H), 7.12 (dd, J=8.0, 2.3 Hz, 1H), 6.82±6.77

(m, 3H), 4.56 (s, 2H), 3.87 (s, 3H), 3.85 (s, 3H), 3.25 (t,

J=7.9 Hz, 2H), 3.00 (t, J=7.8 Hz, 2H), 1.49 (s, 9H); ¹³

C

NMR (CDCl₃, 75 MHz) 199.2, 168.0, 158.6, 149.4,

147.9, 138.7, 134.2, 130.1, 121.8, 120.6, 113.6, 112.3,

111.9, 83.0, 66.1, 56.4, 56.3, 41.1, 30.2, 28.4; LRMS

(ES+): (M+NH₄)⁺418, (M+Na)⁺423.

(R)-1,1-Dimethylethyl [3-[1-hydroxy-3-(3-pyridinyl)propyl]-

phenoxy]-acetate (6f). General procedure D was used

for the alkylation of 4f. The crude product was chro-

matographed (20% then 30% EtOAc/hexane) to aord

product (5.04 g, 89%) as an oil: TLC (EtOAc/hexane, 3/

1) R_f=0.30, (MeOH/CHCl₃, 5/95) R_f=0.32; IR (neat)

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(30%, then 40% EtOAc/hexane) to aord product

(29.0 g, 82%) as a clear colorless oil (98% ee by Chiral-

cel OD HPLC, 25% i-PrOH/hexane, retention time

44.4 min for the R-enantiomer and 35.7 min for the S-

enantiomer): TLC (EtOAc/hexane, 1/1) R_f=0.45; IR

2980, 1750, 1685, 1585, 1440, 1370, 1225, 1155,

1

1080 cm

;

¹H NMR (CDCl₃, 300 MHz) 8.53 (d,

J=1.6 Hz, 1H), 8.45 (d, J=4.0 Hz, 1H), 7.58±7.54 (m,

2H), 7.46 (s, 1H), 7.37 (d, J=8.0 Hz, 1H), 7.21 (dd,

J=7.8, 4.8 Hz, 1H), 7.13 (dd, J=8.2, 2.6 Hz, 1H), 4.56

(s, 2H), 3.29 (t, J=7.4 Hz, 2H), 3.07 (t, J=7.4 Hz, 2H),

1.49 (s, 9H); ¹³C NMR (CDCl₃, 75 MHz) 198.3, 168.0,

158.6, 150.4, 148.1, 138.4, 136.9, 136.4, 130.2, 123.7,

121.8, 120.6, 113.5, 83.0, 66.1, 40.2, 28.4, 27.5; LRMS

(ES+): (M+H)⁺342.

(neat) 3515, 2935, 1750, 1590, 1515, 1450, 1260, 1235,

1

1150, 1080, 1030 cm

;

¹H NMR (CDCl₃, 300 MHz)

7.28±7.23 (m, 1H), 6.98±6.92 (m, 2H), 6.82±6.71 (m,

4H), 4.68±4.64 (m, 1H), 4.52 (s, 2H), 3.86 (s, 3H), 3.85

(s, 3H), 2.70±2.61 (m, 2H), 2.10±1.97 (m, 2H), 1.48 (s,

9H); ¹³C NMR (CDCl₃, 75 MHz) 168.4, 158.6, 149.3,

147.7, 146.9, 134.8, 130.0, 120.6, 119.5, 114.0, 112.6,

112.2, 111.8, 82.7, 74.1, 66.1, 56.3, 56.2, 41.0, 32.0, 28.4;

LRMS (ES+): (M+NH₄)⁺402; HRMS (FAB): (M)⁺

calcd: 402.2042, recorded: 402.2041; (M+Na)⁺calcd:

425.1940, recorded: 425.1941.

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(50% then 80% EtOAc/hexane) to aord product (3.6 g,

78%) as a colorless oil (97.5% ee by Chiralcel OD

HPLC, 20% i-PrOH/hexane, retention time 77 min for

the R-enantiomer and 53 min for the S-enantiomer):

TLC (EtOAc/hexane, 3/1) R_f=0.20, (MeOH/CH₂Cl₂, 5/

(R)-1,1-Dimethylethyl [3-[1-hydroxy-3-(4-methoxyphenyl)-

propyl]phenoxy]-acetate (6e). General procedure C was

used for the alkylation of 4e. The crude product was

chromatographed (20% then 30% EtOAc/hexane) to

aord product (13.1 g, 91%) as an oil: TLC (EtOAc/

hexane, 1/1) R_f=0.70; IR (neat) 2980, 1750, 1685, 1515,

95) R_f= 0.32; IR (neat) 3265, 2980, 1755, 1585, 1480,

1

1445, 1370, 1225, 1150, 1080 cm

;

¹H NMR (CDCl₃,

300 MHz) 8.40±8.10 (m, 2H), 7.50 (d, J=7.8 Hz, 1H),

7.27±7.17 (m, 2H), 6.95±6.92 (m, 2H), 6.81±6.78 (m,

1H), 4.66±4.57 (m, 1H), 4.50 (s, 2H), 3.03 (br s, 1H),

2.75±2.67 (m, 2H), 2.10±1.97 (m, 2H), 1.47 (s, 9H); ¹³C

NMR (CDCl₃, 75 MHz) 168.0, 158.2, 149.7, 147.1,

146.5, 137.3, 136.1, 129.6, 123.4, 119.0, 113.7, 112.1,

82.4, 73.0, 65.7, 40.1, 29.1, 28.1; LRMS (CI+):

(M+H)⁺344; HRMS (FAB): (M)⁺calcd: 343.1784,

recorded: 343.1773.

1

1245, 1155 cm ¹; H NMR (CDCl₃, 300 MHz) 7.56 (d,

J=7.7 Hz, 1H), 7.45 (s, 1H), 7.35 (t, J=8.0 Hz, 1H),

7.16±7.10 (m, 3H), 6.85 (d, J=2.7 Hz, 1H), 4.55 (s, 2H),

3.77 (s, 3H), 3.23 (t, J=7.3 Hz, 2H), 2.99 (t, J=7.8 Hz,

2H), 1.49 (s, 9H); ¹³C NMR (CDCl₃, 75 MHz) 199.2,

168.0, 158.6, 138.7, 133.6, 130.1, 129.7, 121.9, 120.5,

113.6, 83.0, 66.1, 55.7, 41.1, 29.7, 28.4; LRMS (ES+):

(M+H)⁺257; (ES ): (M H) 255.

1-(3-Hydroxyphenyl)-3-(4-morpholinyl)-1-propanone (7).

A solution of morpholine (1.0 mL, 11.5 mmol) in EtOH

(10 mL) was treated with 3⁰-hydroxyacetophenone

(1.56 g, 11.5 mmol) and paraformaldehyde (340 mg,

11.5 mmol) followed by acetic acid (1.3 mL, 23 mmol).

The resulting mixture was heated at re¯ux for 16 h then

cooled and concentrated. The residue was then diluted

with a 5% aqueous HCl solution (10 mL), washed

with diethyl ether (2Â10 mL) followed by neutralization

by addition of solid NaHCO₃. The neutralized aqueous

solution was extracted with diethyl ether (2Â10 mL)

which was then dried over Na₂SO₄, ®ltered, and con-

centrated to a residue. The residue was chromatographed

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(40% EtOAc/hexane) to aord product (5.76 g, 57%) as

an oil (98% ee by Chiralcel OD HPLC, 40% i-PrOH/

hexane, retention time 13.4 min for the R-enantiomer

and 10.7 min for the S-enantiomer): TLC (EtOAc/hex-

ane, 3/7) R_f=0.45; IR (neat) 3500, 2935, 1750, 1610,

1

1510, 1245, 1150 cm

;

¹H NMR (CDCl₃, 300 MHz)

7.27±7.22 (m, 2H), 7.09 (d, J=8.6 Hz, 2H), 6.95±6.90

(m, 2H), 6.83±6.77 (m, 3H), 4.66±4.60 (m, 1H), 4.50 (s,

1322

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

(5% MeOH/CH₂Cl₂) to aord product (680 mg, 25%)

as a brownish oil: TLC (MeOH/CHCl₃, 5/95) R_f=0.22;

IR (neat) 2960, 2855, 1685, 1585, 1450, 1360, 1275,

chromatographed (30% EtOAc/hexane) to aord pro-

duct (3.8 g, 51%) as an oil: TLC (EtOAc/hexane, 1/1)

R_f=0.50; IR (neat) 2975, 1750, 1680, 1600, 1515, 1455,

1

1115, 995, 865 cm ¹; H NMR (CDCl₃, 300 MHz) 7.48

1370, 1260, 1155 cm

;

¹H NMR (CDCl₃, 300 MHz)

(d, J=7.8 Hz, 1H), 7.42 (t, J=2.0 Hz, 1H), 7.32 (t,

J=7.9 Hz, 1H),7.05 (m, 1H), 3.75 (t, J=4.7 Hz, 4H),

3.25 (t, J=7.3 Hz, 2H), 2.87 (t, J=7.3 Hz, 2H), 2.57 (t,

J=4.5 Hz, 4H); ¹³C NMR (CDCl₃, 75 MHz) 199.0,

156.8, 138.1, 123.0, 121.1, 120.1, 114.7, 66.6, 53.6, 53.5,

35.7; LRMS (ES ): (M H) 234.

7.93 (d, J=8.8 Hz, 2H), 6.91 (d, J=8.9 Hz, 2H), 6.78±

6.77 (m, 3H), 4.57 (s, 2H), 3.85 (s, 3H), 3.84 (s, 3H),

3.22 (t, J=7.2 Hz, 2H), 2.99 (t, J=7.9 Hz, 2H), 1.48 (s,

9H); ¹³C NMR (CDCl₃, 75 MHz) 198.2, 167.7, 162.1,

149.3, 147.8, 134.4, 131.1, 130.6, 120.6, 114.7, 112.3,

111.8, 83.1, 65.9, 56.3, 56.2, 40.7, 30.3, 28.4; LRMS

(ES+): (M+H)⁺401, (M+NH₄)⁺418.

(R)-1,1-Dimethylethyl [3-[1-hydroxy-3-(4-morpholinyl)-

propyl]phenoxy]acetate (8). General procedure C was

used for the alkylation of 7. The crude product was

chromatographed (1% MeOH/EtOAc) to aord pro-

duct (10.5 g, 67%) as an oil: TLC (MeOH/CHCl₃, 5/95)

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(30% then 50% EtOAc/hexane) to aord product

(970 mg, 39%) as an oil (99% ee by Chiralcel OD

HPLC, 12.5% i-PrOH/hexane, retention time 56 min for

the R-enantiomer and 52 min for the S-enantiomer):

R_f=0.39; IR (neat) 2975, 1750, 1685, 1585, 1445, 1370,

1

1225, 1155, 1120 cm

;

¹H NMR (CDCl₃, 300 MHz)

7.57 (d, J=7.7 Hz, 1H), 7.46 (s, 1H), 7.38 (t, J=8.0 Hz,

1H), 7.13 (d, J=8.2 Hz, 1H), 4.57 (s, 2H), 3.71 (t,

J=4.7 Hz, 4H), 3.15 (t, J=7.3 Hz, 2H), 2.82 (t,

TLC (EtOAc/hexane, 1/1) R_f=0.25; IR (neat) 3375,

1

2935, 1700, 1515, 1260, 1155 cm

;

¹H NMR (CDCl₃,

300 MHz) 7.27±7.22 (m, 1H), 6.94±6.91 (m, 2H), 6.81±

6.71 (m, 4H), 5.02 (br s, 1H), 4.67±4.63 (m, 1H), 4.01 (t,

J=5.1 Hz, 2H), 3.85 (s, 6H), 3.79±3.67 (m, 2H), 2.73±

2.56 (m, 2H), 2.15±1.93 (m, 2H), 1.45 (s, 9H); ¹³C NMR

(CDCl₃, 75 MHz) 158.8, 155.9, 148.9, 147.3, 146.6,

134.4, 129.6, 120.2, 118.7, 113.5, 112.1, 111.9, 111.4,

79.6, 73.7, 67.2, 56.0, 55.8, 40.6, 40.2, 31.7, 28.4; LRMS

(ES+): (M+Na)⁺454; (ES ): (M H) 430; HRMS

(FAB): (M)⁺calcd: 431.2308, recorded: 431.2301.

J=7.3 Hz, 2H), 2.50 (t, J=4.6 Hz, 4H), 1.49 (s, 9H); ¹³

C

NMR (CDCl₃, 75 MHz) 198.8, 168.0, 158.6, 138.7,

130.1, 121.8, 120.5, 113.6, 83.0, 67.3, 66.1, 54.1, 54.0,

36.5, 28.4; LRMS (ES+): (M+H)⁺350.

General procedure E (3.0 eq of (+)-DIP-Chloride²) was

used for the reduction of the above ketone. The crude

product was chromatographed (5% MeOH/EtOAc) to

aord 270 mg (27%) of an oil that solidi®ed to a waxy

solid on standing (+97% de by comparative integration

of ¹⁹F NMR resonances of the (+)MPTA ester of chiral

and racemic material: TLC (MeOH/CH₂Cl₂, 5/95)

1-(3-Aminophenyl)-3-(3,4-dimethoxyphenyl)-1-propanone

(10). General procedure A was used for the reaction of

3,4,-dimethoxybenzaldehyde and 3⁰-nitroacetophenone.

The crude solids were ®ltered with the aid of EtOAc

(50 mL) to aord 7.0 g of yellow solids. The solids were

recrystallized from ethyl ether/EtOAc to aord product

(4.7 g, 60%) as a orange colored solid: mp 158±159.5 ^ꢂC;

R_f=0.33; IR (neat) 2955, 1750, 1585, 1455, 1370, 1225,

1

1155, 1120, 1075 cm

;

¹H NMR (CDCl₃, 300 MHz)

7.57 (d, J=7.9 Hz, 1H), 6.97 (m, 2H), 6.78 (d,

J=8.1 Hz, 1H), 4.91 (t, J=5.7 Hz, 1H), 4.52 (s, 2H),

3.75 (t, J=4.6 Hz, 4H), 2.70±2.40 (m, 6H), 1.85 (m,

2H), 1.49 (s, 9H); ¹³C NMR (CDCl₃, 75 MHz) 168.5,

158.5, 147.0, 129.7, 119.1, 113.5, 112.4, 83.0, 67.3, 66.1,

54.1, 54.0, 36.5, 28.4; LRMS (ES+): (M+H)⁺352.

HRMS (FAB): (M+H)⁺calcd: 352.2124, recorded:

352.2124.

TLC (EtOAc/hexane, 1/1) R_f=0.41; IR (neat) 1660,

1

1590, 1510, 1350, 1260, 1140, 1020 cm

;

¹H NMR

(CDCl₃, 300 MHz) 8.83 (t, J=1.9 Hz, 1H), 8.43 (ddd,

J=8.1, 2.2, 1.0 Hz, 1H), 8.34 (dt, J=7.7, 1.3 Hz, 1H),

7.85 (d, J=15.5 Hz, 1H), 7.71 (t, J=8.0 Hz, 1H), 7.38

(d, J=15.5 Hz, 1H), 7.28 (dd, J=2.0, 8.4 Hz, 1H), 7.19

(d, J=2.0 Hz, 1H), 6.93 (d, J=8.3 Hz, 1H), 3.98 (s, 3H),

3.95 (s, 3 H); ¹³C NMR (CDCl₃, 75 MHz) 188.4, 152.5,

149.8, 148.8, 147.4, 140.3, 134.5, 130.2, 127.8, 127.2,

124.2, 123.6, 119.0, 111.6, 110.8, 56.5; HRMS (FAB):

(M)⁺calcd: 313.0950, recorded: 313.0943.

(R)-N-(tert-Butoxycarbonyl)-2-[3-[3-[1-hydroxy-3-(3,4-di-

methoxyphenyl)-propyl]phenoxy]ethylamine (9). A solu-

tion of 4d (5.0 g, 17.5 mmol) in DMF (25 mL) was trea-

ted with K₂CO₃(7.2 g, 52 mmol), sodium iodide

(130 mg, 0.87 mmol), and N-tert-butoxycarbonyl-2-bromo-

ethanamine (4.7 g, 19.3 mmol) and heated at 60 ^ꢂC

for 48 h. The reaction mixture was then diluted with

water (125 mL) and extracted with EtOAc (3Â50 mL).

The combined organic extracts were then washed with a

5% aqueous NaOH solution (2Â50 mL) followed by

water (2Â50 mL) and brine (2Â50 mL). The organic layer

was then dried over Na₂SO₄, ®ltered, concentrated, and

General procedure B was used for the reduction of the

above nitrochalcone. The crude product was chromato-

graphed (25% then 50% EtOAc/hexane) to aord pro-

duct (1.2 g, 64%) as a pale-yellow oil which solidi®ed on

standing: TLC (EtOAc/hexane, 1/1) R_f=0.25; IR (neat)

1

3548, 3368, 2934, 1678, 1602, 1515, 1260 cm

;

¹H

NMR (CDCl₃, 300 MHz) 7.32±7.17 (m, 3H), 6.85±6.77

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1323

(m, 4H), 3.85 (s, 3H), 3.84 (s, 3H), 3.75 (br s, 2H), 3.22

(t, J=7.2 Hz, 2H), 2.99 (t, J=7.2 Hz, 2H); ¹³C NMR

(CDCl₃, 75 MHz) 200.0, 149.4, 147.8, 147.2, 138.5,

134.5, 129.8, 120.6, 119.9, 118.7, 114.3, 112.4, 111.9,

56.4, 56.3, 41.1, 30.3; HRMS (FAB): (M+Na)⁺calcd:

308.1263, recorded: 308.1255.

¹³C NMR (CDCl₃, 75 MHz) 198.2, 167.7, 162.1, 149.3,

147.8, 134.4, 131.1, 130.6, 120.6, 114.7, 112.3, 111.8,

83.1, 65.9, 56.3, 56.2, 40.7, 30.3, 28.4; LRMS (ES+):

(M+H)⁺401, (M+NH₄)⁺418.

A

solution of the above tert-butyl ester (2.0 g,

4.99 mmol) in CH₂Cl₂(8 mL) was treated with TFA

(4.0 mL) and the mixture stirred at room temperature

for 6 h. The reaction mixture was diluted with benzene

(50 mL) and concentrated to a solid which was ®ltered

with the aid of benzene to aord product (1.69 g,

98%) as a solid: ¹H NMR (DMSO-d₆, 300 MHz)

7.96 (d, J=8.9 Hz, 1H), 7.01 (d, J=8.9 Hz, 2H),

6.89±6.75 (m, 3H), 4.79 (s, 2H), 3.74 (s, 3H), 3.71 (s,

3H), 3.27 (d, J=7.3 Hz, 1H), 2.86 (d, J=7.6 Hz, 2H);

¹³C NMR (DMSO-d₆, 75 MHz) 198.1, 170.1, 161.9,

148.9, 147.3, 134.1, 130.5, 128.7, 120.4, 114.7, 112.7,

112.2, 64.8, 55.9, 55.7, 39.8, 29.7; LRMS (ES ):

(M H) 343.

(R)-N-(tert-Butoxycarbonyl)-1-(3-aminophenyl)-3-(3,4-di-

methoxyphenyl) propan-1-ol (11). A solution of aniline

10 (440 mg, 1.54 mmol) in CH₂Cl₂(10 mL) was treated

with di-tert-butyl dicarbonate (354 mg, 1.62 mmol) fol-

lowed by DIEA (536 mL, 2.08 mmol). The reaction was

stirred at room temperature for 16 h after which time

the mixture was concentrated and chromatographed

(30% to 50% EtOAc/hexane) to aord product

(290 mg, 97% based on recovered 10 as a colorless solid:

mp 133±134 ^ꢂC; TLC (EtOAc/hexane, 1/1) R_f=0.55; IR

(neat) 3340, 2975, 1725, 1685, 1590, 1515, 1235,

1

1160 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.93 (d,

J=1.5 Hz, 1H), 7.62±7.59 (m, 2H), 7.36 (t, J=7.9 Hz,

1H), 6.79±6.76 (m, 3H), 6.64 (br s, 1H), 3.86 (s, 3H),

3.85 (s, 3H), 3.26 (t, J=7.2 Hz, 2H), 3.00 (t, J=7.2 Hz,

2H), 1.52 (s, 9H); ¹³C NMR (CDCl₃, 75 MHz) 199.5,

153.0, 149.4, 147.9, 139.4, 138.1, 134.3, 129.6, 123.3,

123.0, 120.7, 118.3, 112.4, 111.9, 81.3, 56.4, 41.2, 30.3,

28.7; LRMS (ES+): (M+NH₄)⁺403, (M+Na)⁺408;

(ES ): M 384.

(R)-Trimethylsilylethyl [4-[3-(3,4-dimethoxyphenyl)-1-

hydroxypropyl]-phenoxy]acetate (13). General procedure

F was used for the coupling of acid 12 with 2-(tri-

methylsilyl)ethanol. The crude product was chromato-

graphed (30% EtOAc/hexane) to aord product (3.2 g,

99%) as a colorless oil: TLC (EtOAc/hexane, 3/7)

R_f=0.53; IR (neat) 2955, 1755, 1675, 1600, 1515, 1250,

1

1165, 1025 cm ¹; H NMR (CDCl₃, 300 MHz) 7.95 (d,

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(30%, then 50% EtOAc/hexane) to aord product

(32 mg, 86%) as a colorless oil (98% ee by Chiralcel OD

HPLC, 20% i-PrOH /hexane, retention time 12.3 min

for the R-enantiomer and 14.1 min for the S-enantio-

J=8.9 Hz, 2H), 6.93 (d, J=8.9 Hz, 2H), 6.83±6.77 (m,

3H), 4.66 (s, 2H), 4.32 (t, J=8.5 Hz, 2H), 3.87 (s, 3H),

3.86 (s, 3H), 3.23 (t, J=7.3 Hz, 2H), 3.00 (t, J=8.0 Hz,

2H), 1.03 (td J=4.7, 2.9 Hz, 2H), 0.05 (s, 9H); ¹³C

NMR (CDCl₃, 75 MHz) 199.4, 169.9, 163.1, 150.5,

149.0, 135.6, 132.4, 131.9, 121.7, 115.9, 113.5, 113.0,

66.9, 65.6, 57.5, 57.4, 41.9, 31.5, 18.9, 0.0; LRMS

(ES+): (M+H)⁺445, (M+NH₄)⁺467.

mer): TLC (EtOAc/hexane, 1/1) R_f=0.38; IR (neat)

1

3338, 2934, 1723, 1609, 1517, 1159 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.38 (s, 1H), 7.21 (m, 1H), 7.01±6.98

(m, 1H), 6.78±6.68 (m, 3H), 6.56 (s, 1H), 4.63 (dd,

J=7.4, 5.5 Hz, 1H), 3.83 (s, 3H), 3.82 (s, 3H), 2.68±2.55

(m, 2H), 2.08±1.95 (m, 2H), 1.49 (s, 9H); ¹³C NMR

(CDCl₃, 75 MHz) 152.7, 148.8, 147.2, 145.7, 138.5,

134.4, 129.0, 120.5, 120.2, 117.7, 116.1, 111.8, 111.3,

80.5, 73.7, 55.8, 40.6, 31.6, 28.3; LRMS (ES+):

(M+Na)⁺410; HRMS (FAB): (M+Na)⁺calcd:

410.1943, recorded: 410.1937.

General procedure E was used for the reduction of the

above ketone. The crude product was chromatographed

(30%, EtOAc/hexane) to aord product (455 mg, 91%)

as a clear colorless oil (98% ee by Chiralcel OD HPLC,

30% i-PrOH/hexane, retention time 23.6 min for the

R-enantiomer and 17.9 min for the S-enantiomer): TLC

(EtOAc/hexane, 3/7) R_f=0.28; IR (neat) 3525, 2950,

1

1755, 1610, 1515, 1250, 1175, 1030, 835 cm ¹; H NMR

(CDCl₃, 300 MHz) 7.25±7.21 (m, 2H), 6.86±6.83 (m,

2H), 6,74 (d, J=8.4 Hz, 1H), 6.69±6.66 (m, 2H),

4.61±4.55 (m, 3H), 4.29±4.23 (m, 2H), 3.81 (s, 3H), 3.80

(s, 3H), 2.66±2.50 (m, 2H), 2.10±1.89 (m, 2H), 1.72 (br

s, 1H), 1.01±0.96 (m, 2H), 0.00 (s, 9H); ¹³C NMR

(CDCl₃, 75 MHz) 170.6, 158.9, 150,4, 148.8, 139.4,

135.9, 128.8, 121.7, 116.2, 113.3, 112.9, 74.9, 67.2, 65.3,

57.5, 57.4, 42.1, 33.2, 18.9, 0.00; LRMS (ES+):

(M+Na)⁺469; HRMS(FAB): (M)⁺calcd: 446.2125,

recorded: 446.2120; (M+Na)⁺calcd: 469.2022, recor-

ded: 469.2045.

[4-[3-(3,4-Dimethoxyphenyl)-1-propanone]phenoxy]acetic

acid (12). General procedure C was used for the alkyl-

ation of 5. The crude product was chromatographed

(30% EtOAc/hexane) to aord product (10.1 g, 91%) as

an oil: TLC (EtOAc/hexane, 3/7) R_f=0.29; IR (neat)

2975, 1750, 1680, 1600, 1515, 1455, 1370, 1260,

1

1155 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.93 (d,

J=8.8 Hz, 2H), 6.91 (d, J=8.9 Hz, 2H), 6.78±6.77 (m,

3H), 4.57 (s, 2H), 3.85 (s, 3H), 3.84 (s, 3H), 3.22 (t,

J=7.2 Hz, 2H), 2.99 (t, J=7.9 Hz, 2H), 1.48 (s, 9H);

1324

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

(2S)-1-(3,3,-Dimethyl-1,2-dioxopentyl)-2-piperidinecarb-

oxylic acid (14). The title compound was prepared as

previously described.²⁹

(m, 1H), 5.33 (d, J=4.9 Hz, 1H), 4.55 (s, 2H), 3.38 (d,

J=12.9 Hz, 1H), 3.16 (td, J=12.3, 3.1 Hz, 1H), 2.63±

2.50 (m, 2H), 2.38 (d, J=13.7 Hz, 1H), 2.26±2.16 (m, 1H),

2.09±2.04 (m, 1H), 1.81±1.57 (m, 7H), 1.51 (s, 9H), 1.26,

(s, 3H), 1.23 (s, 3H), 0.91 (t, J=7.4 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.2, 170.0, 168.3, 167.6, 158.5, 148.1,

146.2, 141.7, 135.0, 130.1, 121.5, 120.2, 114.9, 113.6,

109.2, 108.6, 101.2, 82.7, 66.2, 51.7, 47.1, 44.5, 38.3, 32.9,

31.6, 28.4, 26.8, 25.3, 23.8, 23.5, 21.6, 9.1; HRMS (FAB):

(M+Na)⁺calcd: 646.2992, recorded: 646.3021.

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-

3-phenyl-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-

2-piperidinecarboxylate (15a). General procedure F was

used for the coupling of alcohol 6a and acid 14. The

crude product was chromatographed (20% EtOAc/hex-

ane) to aord product (470 mg, 82%) as a colorless oil:

TLC (EtOAc/hexane, 1/4) R_f=0.45; IR (neat) 2955,

1

1750, 1645, 1445, 1225, 1150 cm

;

¹H NMR (CDCl₃,

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-

3-(3,4-dimethoxyphenyl)-1-propanyl (2S)-1-(3,3-dimethyl-

1,2-dioxopentyl)-2-piperidinecarboxylate (15d). General

procedure F was used for the coupling of alcohol 6d and

acid 14. The crude product was chromatographed (25%

then 30% EtOAc/hexane) to aord product (993 mg,

78%) as a colorless oil: TLC (EtOAc/hexane, 3/7)

R_f=0.28; IR (neat) 2940, 1735, 1645, 1515, 1455, 1225,

300 MHz) 7.50±6.90 (m, 9H), 5.93 (t, J=6.0 Hz, 1H),

5.46 (d, J=3.4 Hz, 1H), 4.67 (s, 2H), 3.50 (d,

J=12.9 Hz, 1H), 3.32 (td, J=12.5, 3.0 Hz, 1H), 2.75 (m,

2H), 2.53 (d, J=13.6 Hz, 1H), 2.41 (m, 1H), 2.22 (m,

1H), 1.97±1.71 (m, 7H), 1.62 (s, 9H), 1.38 (s, 3H), 1.35

(s, 3H), 1.03 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 208.3, 175.0, 170.0, 168.0, 167.5, 158.5, 141.7,

141.2, 130.2, 128.9, 128.7, 126.5, 120.2, 114.7, 113.6,

82.8, 66.1, 51.6, 47.1, 44.5, 38.2, 32.9, 32.0, 28.4, 26.8,

25.3, 24.0, 23.4, 21.6, 9.2; HRMS (FAB): (M+Na)⁺

calcd: 602.3094, recorded: 602.3090.

1

1150 cm ¹; H NMR (CDCl₃, 300 MHz) 7.20±7.17 (m,

2H), 6.91±6.69 (m, 5H), 5.73±5.68 (m, 1H). 5.24 (br s,

1H), 4.46 (s, 2H), 3.79 (s, 3H), 3.78 (s, 3H), 3.29 (d,

J=13.2 Hz, 1H), 3.07 (td, J=12.7, 3.0 Hz, 1H), 2.52±

2.44 (m, 2H), 2.29 (d, J=13.6 Hz, 1H), 2.20±2.13 (m,

1H), 2.04±1.95 (m, 1H), 1.71±1.51 (m, 7H), 1.41 (s, 9H),

1.16, (s, 3H), 1.14 (s, 3H), 0.82 (t, J=7.4 Hz, 3H); ¹³C

NMR (CDCl₃, 75 MHz) 208.2, 170.1, 168.3, 167.6, 158.5,

149.3, 147.8, 141.8, 133.9, 130.1, 120.5, 120.3, 114.7,

113.7, 112.2, 111.7, 82.7, 66.2, 56.2, 51.7, 47.1, 44.6, 38.3,

32.9, 31.6, 28.8, 26.8, 25.3, 23.8, 23.5, 21.6, 9.1; HRMS

(FAB): (M+Na)⁺calcd: 662.3305, recorded: 662.3301.

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-

3-(3,4,5-trimethoxyphenyl)-1-propanyl (2S)-1-(3,3-di-

methyl-1,2-dioxopentyl)-2-piperidinecarboxylate (15b).

General procedure F was used for the coupling of alco-

hol 6b and acid 14. The crude product was chromato-

graphed (20% then 30% EtOAc/hexane) to aord

product (776 mg, 78%) as a colorless oil: TLC (EtOAc/

hexane, 2/3) R_f=0.49; IR (neat) 2940, 1745, 1645, 1590,

1

1455, 1240, 1150, 1130 cm

;

¹H NMR (CDCl₃,

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-3-

(4-methoxyphenyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-di-

oxopentyl)-2-piperidinecarboxylate (15e). General proce-

dure F was used for the coupling of alcohol 6e and acid

14. The crude product was ¯ash chromatographed (25%

EtOAc/hexane) to aord product (72 mg, 87%) as a

colorless foam: TLC (EtOAc/hexane, 2/8) R_f=0.35; IR

(neat) 2970, 1750, 1645, 1515, 1440, 1250, 1150 cm ¹; ¹H

NMR (CDCl₃, 300 MHz) 7.29±7.22 (m, 1H), 7.06±6.79

(m, 7H), 5.79±5.74 (m, 1H), 5.30 (d, J=5.0 Hz, 1H), 4.52

(s, 2H), 3.78 (s, 3H), 3.36 (d, J=13.3Hz, 1H), 3.15 (td,

J=12.7, 3.0, 1H), 2.63±2.48 (m, 2H), 2.35 (d, J=13.6Hz,

1H), 2.27±2.17 (m, 1H), 2.08±1.98 (m, 1H), 1.79±1.55 (m,

7H), 1.48 (s, 9H), 1.23 (s, 3H), 1.20 (s, 3H), 0.89 (t,

J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 207.8, 169.7,

167.9, 167.3, 158.2, 141.4, 132.8, 129.7, 129.3, 119.9,

114.3, 113.9, 113.2, 82.3, 65.8, 55.3, 51.3, 46.7, 44.2, 38.0,

32.5, 30.7, 28.1, 26.4, 25.0, 24.5, 23.6, 23.1, 21.2, 8.8;

LRMS (ES+): (M+NH₄)⁺627; (M+Na)⁺632.

300 MHz) 7.30±6.80 (m, 4H), 6.37 (s, 2H), 5.82 (t,

J=6.1 Hz, 1H), 5.33 (d, J=5.2 Hz, 1H), 4.54 (s, 2H),

3.85 (s, 6H), 3.83 (s, 3H), 3.38 (d, J=12.6 Hz, 1H), 3.16

(td, J=12.8, 3.1 Hz, 1H), 2.60 (m, 2H), 2.45±2.05 (m,

3H), 1.70 (m, 6H), 1.50 (s, 9H), 1.45 (m, 2H), 1.25 (s,

3H), 1.23 (s, 3H), 0.90 (t, J=7.4 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.2, 175.1, 170.1, 168.2, 167.6,

158.5, 153.6, 141.7, 137.0, 130.1, 120.9, 120.2, 114.6,

113.7, 105.7, 82.7, 66.2, 61.2, 56.5, 51.7, 47.1, 44.6, 38.2,

32.9, 32.4, 28.4, 26.8, 25.3, 23.9, 23.5, 21.6, 9.1; HRMS

(FAB): (M)⁺calcd: 669.3513, meas: 669.349;

(M+Na)⁺calcd: 692.3411, recorded: 692.3401.

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-

3-(1,3-benzodioxol-5-yl)-1-propanyl (2S)-1-(3,3-dimethyl-

1,2-dioxopentyl)-2-piperidinecarboxylate (15c). General

procedure F was used for the coupling of alcohol 6c acid

and 14. The crude product was chromatographed (20%

then 30% EtOAc/hexane) to aord product (556 mg,

69%) as a colorless oil: TLC (EtOAc/hexane, 3/7)

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-3-

(3-pyridinyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxo-

pentyl)-2-piperidinecarboxylate (15f). General procedure

F was used for the coupling of alcohol 6f and acid 14.

R_f=0.49; IR (neat) 2970, 1745, 1700, 1640, 1490, 1440,

1

1245, 1150 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.32±

7.26 (m, 1H), 6.99±6.84 (m, 6H), 5.93 (s, 2H). 5.80±76

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1325

The crude product was chromatographed (20±60%

EtOAc/hexane) to aord product (860 mg, 96%) as a

colorless oil: TLC (EtOAc/hexane, 1/1) R_f=0.36; IR

(neat) 2970, 1750, 1700, 1645, 1440, 1225, 1150 cm ¹; ¹H

NMR (CDCl₃, 300 MHz) 8.46 (m, 2H), 7.50±6.80 (m,

6H), 5.80 (t, J=6.1 Hz, 1H), 5.32 (d, J=5.0 Hz, 1H),

4.54 (s, 2H), 3.38 (d, J=12.8 Hz, 1H), 3.14 (td, J=12.6,

3.0 Hz, 1H) 2.60 (m, 2H), 2.36 (d, J=13.7 Hz, 1H), 2.25

(m, 1H), 2.10 (m, 1H), 1.75 (m, 4H), 1.49 (s, 9H), 1.45

(m, 2H), 1.24 (s, 3H), 1.22 (s, 3H), 0.90 (t, J=7.4 Hz,

3H); ¹³C NMR (CDCl₃, 75 MHz) 208.2, 175.1, 170.0,

168.2, 167.7, 158.6, 150.2, 148.1, 141.3, 136.6, 130.2,

123.8, 120.1, 115.0, 113.6, 107.9, 82.8, 66.1, 51.7, 47.1,

44.6, 39.2, 37.8, 34.4, 33.0, 29.2, 28.4, 26.7, 25.3, 23.9,

23.5, 21.6, 21.4, 9.1; LRMS (ES+): (M+H)⁺581,

(M+Na)⁺603; (ES ): (M+H)⁺579.

119.6, 114.5, 113.4, 112.2, 111.8, 77.0, 67.6, 56.2, 51.7,

47.1, 44.6, 38.4, 32.9, 31.6, 28.8, 26.9, 25.4, 23.9, 23.5,

21.6, 9.1; LRMS (ES+): (M+H)⁺669, (M+NH₄)⁺

686, (M+H)⁺691.

(1R)-1-[3-N-(tert-Butoxycarbonyl)amino]phenyl]-3-(3,4-di-

methoxyphenyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-di-

oxopentyl)-2-piperidinecarboxylate (19). General proce-

dure F was used for the coupling of alcohol 11 and acid

14. The crude product was chromatographed (30% then

50% EtOAc/hexane) to aord product (130 mg, 43%)

as a white foam: TLC (EtOAc/hexane, 1/1) R_f=0.43; IR

(neat) 2937, 1740, 1702, 1643, 1516, 1146, 1260,

1

1027 cm ¹; H NMR (CDCl₃, 300 MHz) 7.37±7.20 (m,

4H), 6.78±6.65 (m, 3H), 5.81 (t, J=5.7 Hz, 1H), 5.30 (d,

J=4.4 Hz, 1H), 3.83 (s, 6H), 3.34 (d, J=12.3 Hz, 1H),

3.13 (t, J=10.5 Hz, 1H), 2.60±2.52 (m, 2H), 2.35±2.22

(m, 2H), 2.10±2.05 (m, 1H), 1.78±1.55 (m, 7H), 1.41 (s,

9H), 1.23 (s, 3H), 1.20 (s, 3H), 0.89 (t, J=7.4 Hz, 3H);

¹³C NMR (CDCl₃, 75 MHz) 207.7, 169.7, 167.3, 151.9,

149.1, 147.5, 140.7, 139.3, 133.5, 129.1, 127.9, 126.7,

126.1, 120.3, 112.0, 111.6, 83.4, 76.4, 56.0, 55.9, 51.3,

46.7, 44.3, 38.0, 32.5, 31.3, 28.0, 26.5, 25.0, 23.6, 23.2,

21.2, 8.8; HRMS (FAB): (M+Na)⁺calcd: 647.3308,

recorded: 647.3308.

(1R)-1-[3-[2-(1,1-Dimethylethoxy)-2-oxoethoxy]phenyl]-3-

(4-morpholinyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxo-

pentyl)-2-piperidinecarboxylate (16). General proce-

dure F was used for the coupling of alcohol 8 and acid

14. The crude product was chromatographed (75%

EtOAc/hexane) to aord product (831 mg, 72%) as a

colorless oil: TLC (EtOAc) R_f=0.47; IR (neat) 2970,

1

1750, 1645, 1445, 1225, 1150, 990 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.31±7.27 (m, 1H), 6.99 (d,

J=7.9 Hz, 1H), 6.93±6.90 (m, 1H), 6.84 (dd, J=8.2,

2.5 Hz, 1H), 5.89 (t, J=6.9 Hz, 1H), 5.29 (d, J=4.9 Hz,

1H), 4.54 (s, 2H), 3.71 (t, J=4.4 Hz, 4H), 3.36 (d,

J=13.1 Hz, 1H), 3.13 (td, J=12.7, 2.9 Hz, 1H), 2.42±

2.30 (m, 2H), 2.18±2.11 (m, 1H), 2.00±1.91 (m, 1H),

1.79±1.57 (m, 7H), 1.51 (s, 9H), 1.24 (s, 3H), 1.22 (s,

3H), 0.91 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 208.1, 169.9, 168.2, 167.5, 158.5, 141.7, 130.0,

120.1, 82.6, 75.9, 67.3, 66.1, 54.8, 54.0, 51.6, 47.0, 44.5,

33.5, 32.8, 28.4, 26.7, 25.3, 23.9, 23.4, 21.5, 9.1; LRMS

(ES+): (M+H)⁺589.

(1R)-1-[4-[2-(2-Trimethylsilylethoxy)-2-oxoethoxy]phenyl]-

3-(3,4-dimethoxyphenyl)-1-propanyl (2S)-1-(3,3-dimethyl-

1,2-dioxopentyl)-2-piperidinecarboxylate (21). General

procedure F was used for the coupling of alcohol 13

with acid 14. The crude product was chromatographed

(30% EtOAc/hexane) to aord product (760 mg, 83%)

as a colorless oil: TLC (EtOAc/hexane, 3.7) R_f=0.44;

1

IR (neat) 2950, 1735, 1645, 1515, 1445, 1250, 1175 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.25±7.22 (m, 2H), 6.86±

6.82 (m, 2H), 6.73 (d, J=8.6 Hz, 1H), 6.64±6.61 (m,

2H), 5.73 (t, J=6.2 Hz, 1H), 5.24 (d, J=4.8 Hz, 1H),

4.55 (s, 2H), 4.26 (t, J=8.4 Hz, 2H), 3.81 (s, 3H), 3.80 (s,

3H), 3.29 (d, J=13.2 Hz, 1H), 3.04 (td, J=12.7, 3.0 Hz,

1H), 2.57±2.46 (m, 2H), 2.32-2.17 (m, 1H), 2.06±1.99

(m, 1H), 1.71±1.25 (m, 7H), 1.18 (s, 3H), 1.16 (s, 3H),

0.99 (t, J=8.6 Hz, 2H), 0.84 (t, J=7.4 Hz, 3H), 0.00 (s,

9H); ¹³C NMR (CDCl₃, 75 MHz) 209.3, 171.2, 170.4,

168.7, 159.4, 150.5, 148.9, 135.0, 134.4, 129.8, 121.7,

116.2, 112.9, 111.8, 78.0, 67.1, 65.3, 57.4, 52.8 48.2, 45.7,

39.3, 34.0, 32.8, 27.9, 26.5, 25.1, 24.6, 22.7, 18.9, 10.3,

0.0; LRMS (ES+): (M+Na)⁺701.

(1R)-1-[3-[2-[N-(tert-Butoxycarbonyl)ethanamine]phenoxy]-

3-(3,4-dimethoxyphenyl)-1-propanyl (2S)-1-(3,3-dimethyl-

1,2-dioxopentyl)-2-piperidinecarboxylate (17). General

procedure F was used for the coupling of alcohol 9 and

acid 14. The crude product was chromatographed (30%

then 40% EtOAc/hexane) to aord product (447 mg,

64%) as an oil: TLC (EtOAc/hexane, 2/3) R_f=0.40; IR

(neat) 3380, 2970, 1700, 1645, 1515, 1455, 1260, 1160,

1

1030 cm ¹; H NMR (CDCl₃, 300 MHz) 7.29±7.24 (m,

2H), 6.94±6.77 (m, 3H), 6.70±6.67 (m, 2H), 5.80±5.75

(m, 1H), 5.32 (d, J=5.0 Hz, 1H), 5.02 (br s, 1H), 4.03 (t,

J=5.1 Hz, 2H), 3.86 (s, 3H), 3.85 (s, 3H), 3.54±3.52 (m,

2H), 3.37 (d, J=13.3 Hz, 1H), 3.16 (td, J=12.6, 2.9 Hz,

1H), 2.64±2.51 (m, 2H), 2.37 (d, J=13.5 Hz, 1H), 2.31±

2.18 (m, 1H), 2.13±1.92 (m, 1H), 1.78±1.50 (m, 7H), 1.45

(s, 9H), 1.23 (s, 3H), 1.21 (s, 3H), 0.89 (t, J=7.4 Hz,

3H); ¹³C NMR (CDCl₃, 75 MHz) 208.2, 170.1, 167.6,

159.2, 156.3, 149.3, 147.8, 141.9, 133.9, 130.1, 120.6,

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-phenyl-1-propanyl

(2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-piperidinecarboxy-

late (2a). General procedure G was used for the acid-

olysis of 15a. The crude product was chromatographed

(10% MeOH/CH₂Cl₂) to aord product (177 mg, 99%)

as

R_f=0.35; IR (neat) 2940, 1740, 1700, 1640, 1445,

a colorless gum: TLC (MeOH/CHCl₃, 15/85)

1

1200 cm ¹; H NMR (CDCl₃, 300 MHz) 7.30±6.80 (m,

1326

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

9H), 5.75 (m, 1H), 5.30 (d, J=4.8 Hz, 1H), 4.66 (s, 2H),

3.35 (d, J=9.27 Hz, 1H), 3.19 (td, J=12.4, 2.9 Hz, 1H),

2.69 (m, 2H), 2.39 (d, J=16.2 Hz, 1H), 2.30 (m, 1H),

2.10 (m, 1H), 1.90±1.60 (m, 6H), 1.50 (m, 1H), 1.19 (s,

3H), 1.17 (s, 3H), 0.85 (t, J=7.4 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.0, 172.3, 169.8, 167.9, 158.2,

142.2, 141.1, 130.2, 128.9, 128.7, 126.5, 120.3, 115.5,

111.8, 65.5, 57.2, 52.0, 47.2, 44.6, 38.3, 33.0, 32.9, 32.1,

27.0, 25.3, 25.2, 23.9, 23.4, 21.5, 9.1; HRMS (FAB):

(M+Na)⁺calcd: 546.2468, recorded: 546.2461.

product (315 mg, 86%) as a foam: TLC (MeOH/CHCl₃,

15/85) R_f=0.35; IR (neat) 2940, 1740, 1640, 1515, 1445,

1

1260, 1160 cm ¹; H NMR (CDCl₃, 300 MHz) 8.00 (br

s, 1H), 7.35±6.70 (m, 7H), 5.82 (m, 1H), 5.33 (d,

J=4.5 Hz, 1H), 4.71 (m, 2H), 3.89 (s, 3H), 3.87 (s, 3H),

3.38 (d, J=12.6 Hz, 1H), 3.24 (td, J=12.3, 2.7 Hz, 1H),

2.60 (m, 2H), 2.45±2.05 (m, 3H), 1.70 (m, 6H), 1.45 (m,

2H), 1.23 (s, 3H), 1.21 (s, 3H), 0.89 (t, J=7.4 Hz, 3H);

¹H NMR (CD₃OD, 300 MHz) 7.30 (t, J=7.9 Hz, 1H),

7.00±6.77 (m, 5H), 6.72 (dd, J=8.1, 1.8 Hz, 1H), 5.80±

5.74 (m, 1H), 5.24 (d, J=4.5 Hz, 1H), 4.69 (s, 2H), 3.82

(s, 3H), 3.80 (s, 3H), 3.38 (dd, J=13.3, 8.5 Hz, 1H), 3.18

(td, J=12.8, 2.9 Hz, 1H), 2.69±2.54 (m, 2H), 2.37±2.15

(m, 2H), 2.13±2.01 (m, 1H), 1.79±1.61 (m, 5H), 1.53±

1.30 (m, 2H), 1.25 (s, 3H), 1.23 (s, 3H), 0.90 (t,

J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 208.0,

172.0, 169.8, 167.8, 158.2, 149.4, 147.8, 142.2, 133.7,

130.2, 129.4, 128.6, 125.7, 120.6, 120.3, 115.5, 112.2,

111.8, 111.7, 108.2, 65.5, 56.3, 51.9, 47.2, 44.6, 38.5,

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(3,4,5-trimethoxy-

phenyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-

2-piperidinecarboxylate (2b). General procedure G was

used for the acidolysis of 15b. The crude product was

chromatographed (10% MeOH/CH₂Cl₂) to aord pro-

duct (358 mg, 98%) as a white foam: TLC (MeOH/

CHCl₃, 15/85) R_f=0.40; IR (neat) 3445, 2940, 1735,

;

¹H NMR (CDCl₃,

1

1700, 1635, 1460, 1210, 1130 cm

300 MHz) 7.30±6.80 (m, 4H), 6.39 (s, 2H), 5.82 (m, 1H),

5.33 (d, J=4.6 Hz, 1H), 4.70 (m, 2H), 3.86 (s, 6H), 3.84

(s, 3H), 3.38 (d, J=12.6 Hz, 1H), 3.22 (td, J=12.8,

3.1 Hz, 1H), 2.60 (m, 2H), 2.45±2.05 (m, 3H), 1.70 (m,

6H), 1.45 (m, 2H), 1.23 (s, 3H), 1.21 (s, 3H), 0.89 (t,

J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 208.0,

175.0, 171.7, 169.8, 167.8, 158.2, 153.6, 142.1, 136.9,

130.2, 129.4, 128.6, 125.7, 120.3, 115.5, 111.8, 107.9,

105.8, 65.6, 61.2, 56.5, 52.0, 47.2, 44.6, 38.3, 32.9, 32.5,

27.0, 25.3, 23.8, 23.4, 21.5, 9.1; HRMS (FAB):

(M+Na)⁺calcd: 636.2785, recorded: 636.2756.

32.9, 31.7, 28.4, 27.0, 25.3, 23.9, 23.4, 21.8, 21.5, 9.1; ¹³

C

NMR (CD₃OD, 75 MHz) 207.9, 171.4, 169.8, 167.9,

158.5, 149.3, 147.7, 142.0, 134.1, 129.6, 120.5, 119.7,

114.4, 112.7, 112.4, 112.1, 76.8, 64.8, 55.4, 55.3, 51.6,

46.5, 44.6, 37.9, 32.4, 31.0, 26.1, 24.7, 22.7, 22.4, 20.9,

7.9; HRMS (FAB): (M+Na)⁺calcd: 606.2679, recor-

ded: 606.2692.

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(4-methoxyphenyl)-

1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-piper-

idinecarboxylate (2e). General procedure G was used

for the acidolysis of 15e. The crude product was chro-

matographed (10% MeOH/CH₂Cl₂) to aord product

(45 mg, 71%) as a foam: TLC (MeOH/CHCl₃, 15/85)

R_f=0.35; IR (neat) 2940, 1735, 1700, 1635, 1455,

1210 cm ¹; ¹H NMR (CD₃OD, 300 MHz) 7.14±7.00 (m,

1H), 6.85 (d, J=8.1 Hz, 2H), 6.77±6.67 (m, 3H), 6.61

(d, J=8.2 Hz, 2H), 5.55±5.50 (m, 1H), 5.01 (d,

J=4.5 Hz, 1H), 4.45 (s, 2H), 3.54 (s, 3H), 3.18 (d,

J=13.0 Hz, 1H), 2.95 (t, J=12.6 Hz, 1H), 2.45±2.25

(m, 2H), 2.20±1.80 (m, 3H), 1.60±1.40 (m, 5H), 1.35±

1.10 (m, 2H), 1.02 (s, 3H), 1.00 (s, 3H), 0.67 (t,

J=7.4 Hz, 3H); ¹³C NMR (CD₃OD, 75 MHz) 210.0,

171.9, 170.1, 160.7, 160.5, 144.1, 135.3, 131.8, 131.4,

121.85, 116.6, 116.0, 116.0, 114.9, 79.1, 56.7, 53.8, 48.7,

46.7, 40.2, 34.6, 32.8, 28.3, 26.9, 24.9, 24.6, 23.1, 10.1;

LRMS (ES+): (M+Na)⁺576; (ES ): (M H) 552;

HRMS (FAB): (M H) calcd: 552.2597, recorded:

552.2585.

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(1,3-benzodioxol-

5-yl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-

piperidinecarboxylate (2c). General procedure G was

used for the acidolysis of 15c. The crude product was

chromatographed (10% MeOH/CH₂Cl₂) to aord pro-

duct (483 mg, 85%) as a colorless oil: TLC (MeOH/

CHCl₃, 15/85) R_f=0.40; IR (neat) 3420, 2940, 1735,

1

1700, 1640, 1490, 1440, 1245, 1040 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.12 (t, J=6.7 Hz, 1H), 6.92±6.81

(m, 3H), 6.68±6.52 (m, 3H), 5.86 (s, 2H), 5.73 (t,

J=7.2 Hz, 1H), 5.33 (s, 1H), 4.40 (s, 2H), 3.34 (d,

J=12.2 Hz, 1H), 3.19 (t, J=12.0 Hz, 1H), 2.54±2.46 (m,

2H), 2.34 (d, J=12.6 Hz, 1H), 2.24±2.00 (m, 2H), 1.73±

1.32 (m, 7H), 1.18 (s, 3H), 1.16 (s, 3H), 0.84 (t,

J=7.3 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 208.0,

169.9, 167.79, 158.3, 148.0, 146.2, 141.9, 135.0, 130.1,

121.5, 109.1, 108.6, 107.2, 101.2, 77.0, 51.9, 47.0, 44.6,

38.6, 32.9, 31.8, 26.9, 25.3, 23.9, 23.3, 21.6, 9.1. HRMS

(FAB): (M H) calcd: 566.2390, recorded: 566.2365.

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(3-pyridinyl)-1-prop-

anyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-piperidine-

carboxylate (2f). General procedure G was used for the

acidolysis of 15f. The crude product was not chromato-

graphed. Product (424 mg, 96%, as tri¯uoroacetic acid

salt) was obtained as a foam: ¹H NMR (CDCl₃,

300 MHz) 8.75 (s, 1H), 8.67 (d, J=10.4 Hz, 1H), 8.23

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(3,4-dimethoxy-

phenyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-

2-piperidinecarboxylate (2d). General procedure G was

used for the acidolysis of 15d. The crude product was

chromatographed (10% MeOH/CH₂Cl₂) to aord

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1327

(t, J=5.6 Hz, 1H), 7.79 (dd, J=7.9, 5.6 Hz, 1H), 7.35±

6.75 (m, 4H), 5.80 (t, J=6.1 Hz, 1H), 5.25 (d,

J=5.0 Hz, 1H), 4.75 (m, 2H), 3.35 (d, J=13.2 Hz, 1H),

3.14 (td, J=12.6, 3.0 Hz, 1H) 2.75 (m, 2H), 2.30 (m,

3H), 1.70 (m, 6H), 1.40 (m, 2H), 1.22 (s, 6H), 0.92 (t,

J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 208.3,

172.3, 169.9, 167.8, 158.6, 145.5, 142.5, 142.0, 139.8,

139.5, 130.6, 129.4, 128.6, 120.2, 117.1, 111.8, 65.2, 51.8,

47.1, 44.8, 36.7, 32.8, 28.4, 26.6, 25.2, 23.7, 21.4, 9.1.

HRMS (FAB): (M+Na)⁺calcd: 547.2420, recorded:

547.2415.

(50% EtOAc/hexane with 1% AcOH) to aord product

(313 mg, 77%) as a foam: TLC (EtOAc/hexane 1:1, with

1% AcOH) R_f=0.43; IR (neat) 3370, 2940, 1740, 1700,

1

1640, 1515, 1200, 1140 cm

;

¹H NMR (CDCl₃,

300 MHz) 7.26±6.67 (m, 7H), 6.03 (br s, 2H), 5.76 (t,

J=5.7 Hz, 1H), 5.31 (d, J=4.8 Hz, 1H), 3.84 (s, 6H),

3.83 (s, 3H), 3.35 (d, J=12.6 Hz, 1H), 3.14 (t,

J=10.1 Hz, 1H), 2.63±2.49 (m, 2H), 2.38±2.10 (m, 2H),

22.08±2.00 (m, 1H), 1.77±1.60 (m, 5H), 1.56±1.37 (m,

2H), 1.21 (s, 3H), 1.19 (s, 3H), 0.86 (t, J=7.4 Hz, 3H);

¹³C NMR (CDCl₃, 75 MHz) 208.3, 170.0, 167.7, 149.3,

147.8, 141.6, 133.9, 130.1, 129.4, 128.6, 120.6, 118.2,

116.3, 112.2, 111.8, 76.9, 56.3, 56.2, 51.7, 47.1, 44.6,

38.4, 31.9, 31.6, 26.7, 25.3, 23.0, 21.5, 9.1; HRMS

(FAB): (M)⁺calcd: 547.2784, recorded: 547.2790.

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(4-morpholinyl)-1-

propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-piper-

idinecarboxylate (2g). General procedure H was used

for the acidolysis of 16. The crude product was not

chromatographed. Product (297 mg, 95%, as hydro-

(1R)-1-[4-(Carboxymethoxy)phenyl]-3-(3,4-dimethoxy-

phenyl)-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-

2-piperidinecarboxylate (22). A solution of ester 21

(150 mg, 0.219 mmol) in DMF (2 mL) at 0 ^ꢂC was trea-

ted with a solution of tetrabutylammonium ¯uoride in

THF (1.0 N, 439 mL, 0.439 mmol). The reaction mixture

was allowed to stir for 1 h then partitioned between

EtOAc (10 mL) and a 0.5 N HCl solution (10 mL). The

organic layer was washed with an additional portion of

0.5 N HCl solution followed by brine (2Â10 mL), then

dried over Na₂SO₄, ®ltered, evaporated, and chromato-

graphed (5% then 10% MeOH/CH₂Cl₂) to aord pro-

duct (110 mg, 86%) as a colorless foam: TLC (MeOH/

chloric acid salt) was obtained as a foam: IR (neat)

1

2970, 1740, 1700, 1635, 1445, 1200, 1080 cm

;

¹H

NMR (CDCl₃, 300 MHz) 11.80 (br s, 1H), 7.19±71.3 (m,

1H), 6.82±6.76 (m, 2H), 5.75 (br s, 1H), 5.11 (d,

J=4.9 Hz, 1H), 4.52 (s, 2H), 4.02 (br s, 2H), 3.79 (d,

J=11.8 Hz, 1H), 3.35±3.20 (m, 2H), 3.09±2.74 (m, 5H),

2.35±2.21 (m, 3H), 1.66±1.16 (m, 7H), 1.11 (s, 3H), 1.10

(s, 3H), 0.78 (t, J=7.4 Hz, 1H); ¹³C NMR (CDCl₃,

75 MHz) 209.0, 170.7, 169.7, 168.0, 158.5, 139.7, 130.6,

119.6, 116.1, 112.4, 65.5, 64.0, 54.1, 52.8, 52.3, 51.9,

47.1, 45.0, 32.8, 30.0, 26.4, 25.1, 23.9, 23.4, 21.4, 9.1;

LRMS (ES+): (M+H)⁺533; (ES ): (M H) 531;

HRMS (FAB): (M H) calcd: 531.2706, recorded:

531.2712.

CHCl₃, 15/85) R_f=0.40; IR (neat) 2940, 1735, 1640,

1

1515, 1445, 1235 cm

;

¹H NMR (CDCl₃, 300 MHz)

7.32±7.26 (m, 2H), 6.92±6.89 (m, 2H), 6.78 (d,

J=8.7 Hz, 1H), 6.69±6.66 (m, 2H), 5.78 (t, J=6.2 Hz,

1H), 5.29 (d, J=4.8 Hz, 1H), 4.67 (s, 2H), 3.85 (s, 6H),

3.34 (d, J=13.4 Hz, 1H), 3.09 (td, J=12.6, 3.0 Hz, 1H),

2.59±2.50 (m, 2H), 2.37±2.23 (m, 2H), 2.08±2.03 (m,

1H), 1.75±1.25 (m, 7H), 1.23 (s, 3H), 1.20 (s, 3H), 0.89

(t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 208,

172.3, 170.1, 167, 157.7, 149.3, 147.8, 133.9, 133.8,

128.8, 120.6, 115.2, 112.2, 111.8, 77.0, 65.3, 56.3, 56.2,

51.7, 47.1, 44.6, 38.1, 32.9, 31.7, 26.8, 25.3, 23.9, 23.5,

21.6, 9.1; LRMS (ES+): (M+NH₄)⁺601. HRMS

(FAB): (M)⁺calcd: 583.2781, recorded: 583.2763;

(M+Na)⁺calcd: 606.2679, recorded: 606.2680.

(1R)-3-(3,4-Dimethoxyphenyl)-1-[3-[2-ethanamine]phen-

oxy]-1-propanyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-

piperidinecarboxylate hydrochloride (18). General proce-

dure H was used for the acidolysis of 17. The crude

hydrochloride salt product was not chromatographed.

Product was obtained as a foam: IR (neat) 2965, 1735,

;

¹H

1

1700, 1640, 1515, 1455, 1260, 1160, 1025 cm

NMR (CDCl₃, 300 MHz) 8.53 (br s, 2H), 7.30±7.10 (m,

1H), 7.00±6.68 (m, 6H), 5.80±5.70 (m, 1H), 5.35±5.30

(m, 1H), 4.30±4.15 (m, 1H), 3.85 (s, 3H), 3.83 (s, 3H),

3.40±3.20 (m, 3H), 3.15 (t, J=12.0 Hz, 1H), 2.32±2.15

(m, 1H), 2.13±2.00 (m, 1H), 1.80±1.30 (m, 8H), 1.20 (s,

3H), 1.18 (s, 3H), 0.86 (t, J=7.1 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.3, 170.1, 167.7, 158.3, 149.3,

147.8, 142.1, 133.9, 130.2, 120.6, 112.0, 114.7, 113.7,

112.3, 111.8, 77.1, 64.0, 56.3, 51.8, 47.1, 44.6, 39.5, 38.7,

32.8, 31.7, 26.8, 25.3, 23.8, 23.5, 21.6, 9.1; LRMS

(ES+): (M+H)⁺569; HRMS (FAB): (M+H)⁺calcd:

569.3227, recorded: 569.3247.

Dimer (1a). General procedure I was used for the

dimerization of 2a. The crude product was chromato-

graphed (75% then 100% EtOAc/hexane) to aord

product (470 mg, 82%) as a foam: TLC (EtOAc/hexane,

3/1) R_f=0.45; IR (neat) 3350, 2940, 1740, 1675, 1644,

1

1540, 1442, 1265, 1200, 1075, 990 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.27±7.12 (m, 6H), 6.99±6.83 (m,

3H), 5.82±5.80 (m, 1H), 5.32 (s, 1H), 4.43 (s, 2H), 3.54

(s, 2H), 3.37 (d, J=12 Hz, 1H), 3.18 (t, J=12 Hz, 1H),

2.66±2.53 (m, 2H), 2.39±2.11 (m, 3H), 1.87±1.63 (m,

5H), 1.53±1.35 (m, 2H), 1.22 (s, 6H), 0.88 (t, J=7.4 Hz,

(1R)-1-(3-Aminophenyl)-3-(3,4-dimethoxyphenyl)-1-prop-

anyl (2S)-1-(3,3-dimethyl-1,2-dioxopentyl)-2-piperidine-

carboxylate (20). General procedure G was used for the

acidolysis of 19. The crude product was chromatographed

1328

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

3H); ¹³C NMR (CDCl₃, 75 MHz) 208.25, 170.0, 169.6,

167.7, 157.8, 142.2, 141.2, 130.4, 128.9, 128.7, 126.5,

120.5, 114.5, 113.8, 76.9, 67.6, 51.7, 47.1, 44.5, 39.8,

38.4, 32.9, 32.0, 25.3, 24.9, 23.9, 23.5, 21.6, 9.1; HRMS

(FAB): (M+Na)⁺calcd: 1093.5514, recorded: 1093.5536.

J=4.7 Hz, 1H), 4.45 (s, 2H), 3.85 (s, 6H), 3.54 (s, 2H),

3.38 (d, J=12.4 Hz, 1H), 3.18 (t, J=10.4, 1H), 2.72±

2.52 (m, 2H), 2.37 (d, J=13.1 Hz, 1H), 2.30±2.21 (m,

1H), 2.11±2.02 (m, 1H), 1.74±1.62 (m, 5H), 1.51±1.33

(m, 2H), 1.22 (s, 6H), 0.88 (t, J=7.4 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.3, 170.0, 169.6, 167.7, 157.8,

149.3, 147.8, 142.3, 133.8, 130.3, 120.6, 114.5, 113.8,

112.2, 111.8, 76.8, 67.6, 56.2, 51.7, 47.1, 44.5, 39.8,

38.5, 32.9, 31.6, 26.8, 25.3, 23.9, 23.8, 21.5, 9.1;

HRMS (FAB): (M+Na)⁺calcd: 1213.5937, recorded:

1213.5905.

Dimer (1b). General procedure I was used for the

dimerization of 2b. The crude product was chromato-

graphed (50% then 75% EtOAc/hexane then EtOAc) to

aord product (65 mg, 66%) as a colorless foam: TLC

(EtOAc/hexane, 3/1) R_f=0.15; IR (neat) 3360, 2940,

1

1740, 1645, 1590, 1445, 1240, 1130 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.31±7.26 (m, 2H), 7.00±6.97 (m,

2H), 6.87±6.84 (m, 1H), 6.40±6.36 (m, 2H), 5.81±5.78

(m, 1H), 5.31 (d, J=4.8 Hz, 1H), 4.45 (s, 2H), 3.83 (s,

6H), 3.81 (s, 3H), 3.54, (s, 2H), 3.38 (d, J=1.8 Hz, 1H),

3.17 (td, J=12.7, 2.5 Hz, 1H), 2.62±2.53 (m, 2H), 2.36

(d, J=13.6 Hz, 1H), 2.29±2.22 (m, 1H), 2.12±2.02 (m,

1H), 1.74±1.62 (m, 7H), 1.22 (s, 3H), 1.21 (s, 3H), 0.88

(d, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 207.9,

169.7, 169.2, 167.3, 157.5, 153.2, 141.9, 136.6, 130.0,

120.1, 114.0, 113.5, 76.5, 67.3, 60.8, 56.1, 51.3, 46.7,

44.2, 39.5, 38.1, 32.6, 32.1, 26.4, 25.0, 23.3, 21.0, 8.8;

HRMS (FAB): (M+Na)⁺calcd: 1273.6148, recorded:

1273.6193.

Compound 1d was also prepared from the DCC cou-

pling of diol 28 with acid 14 via general procedure K.

The crude product was chromatographed (75% EtOAc/

hexane then EtOAc) to aord product (196 mg, 94%)

identical in all respects to that obtained above.

Dimer (1e). General procedure I was used for the

dimerization of 2e. The crude product was chromato-

graphed (75% then 100% EtOAc/hexane) to aord

product (33 mg, 37%) as

(EtOAc) R_f=0.33; IR (neat) 3360, 2940, 1740, 1680,

a colorless foam: TLC

1

1645, 1515, 1445, 1260, 1160, 1030 cm

;

¹H NMR

(CDCl₃, 300 MHz) 7.30±7.25 (m, 2H), 7.05 (d,

J=8.5 Hz, 2H), 6.98±6.94 (m, 1H), 6.83±6.79 (m, 3H),

5.77 (dd, J=7.3, 5.8 Hz, 1H), 5.30 (d, J=4.9 Hz, 1H),

4.44 (s, 2H), 3.77 (s, 3H), 3.54 (s, 2H), 3.37 (d,

J=13.4 Hz, 1H), 3.17 (td, J=12.6, 2.5, 1H), 2.63±2.49

(m, 2H), 2.36 (d, J=13.6 Hz, 1H), 2.28±2.15 (m, 1H),

2.08±2.01 (m, 1H), 1.79±1.60 (m, 5H), 1.51±1.30 (m,

2H), 1.22 (s, 3H), 1.20 (s, 3H), 0.88 (t, J=7.4 Hz, 3H);

¹³C NMR (CDCl₃, 75 MHz) 207.13, 168.8, 168.4, 168.3,

166.5, 157.24, 156.7, 141.1, 132.1, 129.2, 128.5, 119.3,

113.2, 112.6, 76.7, 66.5, 54.5, 50.5, 46.0, 43.4, 38.7, 37.5,

31.7, 30.0, 25.7, 24.2, 22.7, 22.4, 20.42, 8.0; LRMS

(ES+): (M+H)⁺1131, (M+Na)⁺1153; HRMS

(FAB): (M+Na)⁺calcd: 1153.5725, recorded: 1153.2757.

Dimer (1c). General procedure I was used for the

dimerization of 2c. The crude product was chromato-

graphed (50% EtOAc/hexane) to aord product (38 mg,

27%) as a colorless foam: TLC (EtOAc/hexane, 3/1)

R_f=0.39; IR (neat) 3355, 2940, 1740, 1675, 1645, 1540,

1

1490, 1440, 1245, 1190, 1040 cm

;

¹H NMR (CDCl₃,

300 MHz) 7.36±7.25 (m, 2H), 7.00±6.91 (m, 2H), 6.84 (d,

J=8.1 Hz, 1H), 6.72±6.56 (m, 3H), 5.90 (s, 2H), 5.77 (t,

J=5.7 Hz, 1H), 5.29 (d, J=4.8 Hz, 1H), 4.44 (s, 2H),

3.55 (s, 2H), 3.37 (d, J=12.5 Hz, 1H), 3.16 (td, J=12.6,

2.6 Hz, 1H), 2.60±2.47 (m, 2H), 2.36 (d, J=13.3 Hz,

1H), 2.26±2.17 (m, 1H), 2.09±1.99 (m, 1H), 1.86±1.27

(m, 7H), 1.22 (s, 3H), 1.20 (s, 3H), 0.88 (d, J=7.4 Hz,

3H); ¹³C NMR (CDCl₃, 75 MHz) 208.3, 170.0, 169.6,

167.7, 157.8, 148.1, 146.2, 142.2, 135.0, 130.4, 121.5,

120.5, 114.5, 113.8, 109.1, 108.6, 76.7, 67.6, 51.7, 47.1,

44.5, 39.9, 38.6, 32.9, 31.7, 26.8, 25.3, 23.9, 23.5, 21.6,

9.1; HRMS (FAB): (M+Na)⁺calcd: 1181.5311, recor-

ded: 1181.5317.

Dimer (1f). General procedure J was used for the

dimerization of 2f. Ethylenediamine dihydrochloride

was used as the coupling reagent. The crude product

was chromatographed (10% MeOH/CH₂Cl₂) to aord

product (79 mg, 42% from succinimidyl ester) as a color-

less foam: TLC (MeOH/CHCl₃, 1/9) R_f=0.29; IR

(neat) 3335, 2940, 1735, 1670, 1640, 1540, 1440, 1265,

1

Dimer (1d). General procedure J was used for the

dimerization of 2d. Ethylenediamine dihydrochloride

was used as the coupling reagent. The crude product

was chromatographed (75% then 100% EtOAc/hexane)

to aord product (562 mg, 42%) as a colorless foam:

1200 cm ¹; H NMR (CDCl₃, 300 MHz) 8.45±8.41 (m,

2H), 7.50 (d, J=7.8 Hz, 1H), 7.35±7.20 (m, 3H), 7.00±

6.92 (m, 1H), 6.85 (dd, J=8.0, 2.1 Hz, 1H), 5.82±5.77

(m, 1H), 5.31 (d, J=4.9 Hz, 1H), 4.45 (s, 2H), 3.56 (br

s, 2H), 3.37 (d, J=12.6 Hz, 1H), 3.16 (td, J=12.6,

2.8 Hz, 1H), 2.66±2.56 (m, 3H), 2.36 (d, J=5.5 Hz, 1H),

2.28±2.22 (m, 1H), 2.15±2.05 (m, 1H), 1.80±1.36 (m,

7H), 1.22 (s, 3H), 1.21 (s, 3H), 0.88 (d, J=7.4 Hz,

3H); ¹³C NMR (CDCl₃, 75 MHz) 208.3, 170.0, 169.6,

167.7, 157.9, 149.8, 147.7 141.8, 136.6, 130.5, 123.9,

TLC (EtOAc) R_f=0.33; IR (neat) 3360, 2940, 1740,

1

1680, 1645, 1515, 1445, 1260, 1160, 1030 cm

;

¹H

NMR (CDCl₃, 300 MHz) 7.30±7.25 (m, 2H), 6.98±6.93

(m, 1H), 6.85 (d, J=8.0 Hz, 1H), 6.78 (t, J=6.3 Hz,

1H), 6.76±6.68 (m, 2H), 5.80 (d, J=5.6 Hz, 1H), 5.31 (d,

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1329

121.7, 120.3, 114.5, 113.8, 76.5, 67.6, 51.7, 47.1, 44.6,

39.9, 37.9, 32.9, 39.1, 26.7, 25.3, 23.8, 23.6, 21.5, 9.1;

HRMS (FAB): (M+Na)⁺calcd: 1095.5419, recorded:

1095.5450.

J=13.3 Hz, 1H), 3.19 (td, J=12.7, 2.7, 1H), 2.64±2.52

(m, 2H), 2.36 (d, J=13.4 Hz, 1H), 2.270±2.20 (m, 1H),

2.10±2.00 (m, 1H), 1.79±1.32 (m, 7H), 1.22 (s, 3H), 1.20

(s, 3H), 0.88 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 207.8, 169.7, 168.2, 167.3, 157.4, 149.0, 147.5,

142.0, 133.4, 130.3, 120.2, 114.2, 113.3, 111.8, 111.4,

76.5, 69.6, 67.4, 55.9, 51.2, 46.7, 44.2, 38.8, 38.2, 32.5,

31.3, 26.4, 25.0, 23.6, 23.5, 21.2, 8.8; HRMS (FAB):

(M+Na)⁺calcd: 1257.6199, recorded: 1257.6193.

Dimer (1g). General procedure I was used for the

dimerization of 2g. The crude product was chromato-

graphed (10% MeOH/CH₂Cl₂) to aord product

(220 mg, 77%) as a colorless foam: TLC (MeOH/

CHCl₃, 1/9) R_f=0.38; IR (neat) 3330, 2940, 1740, 1670,

1

1640, 1540, 1445, 1265, 1205, 1115 cm

;

¹H NMR

Dimer (1k). General procedure J was used for the

dimerization of 2d. The diamine 2,2⁰-(ethylenedioxy)-

bis(ethylamine) replaces ethylenediamine as the cou-

pling reagent. The crude product was chromatographed

(5% MeOH/EtOAc) to aord product (54 mg, 49%) as

a colorless foam: TLC (EtOAc) R_f=0.15; IR (neat)

3365, 2940, 1735, 1680, 1645, 1515, 1445, 1260,

(CDCl₃, 300 MHz) 7.34±7.26 (m, 2H), 7.00±6.94 (m,

2H), 6.88±6.85 (m, 1H), 5.88 (t, J=6.3 Hz, 1H), 5.28 (d,

J=4.7 Hz, 1H), 4.46 (s, 2H), 3.71 (br s, 4H), 3.55 (s,

2H), 3.36 (d, J=12.9 Hz, 1H), 3.15 (td, J=12.7, 2.7 Hz,

1H), 2.43±2.33 (m, 7H), 2.21±2.15 (m, 1H), 1.99±1.91

(m, 1H), 1.73±1.27 (m, 7H), 1.22 (s, 3H), 1.20 (s, 3H),

0.88 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz)

208.0, 169.5, 169.2, 167.2, 157.4, 141.7, 130.0, 120.0,

114.0, 113.3, 75.2, 67.1, 66.8, 54.4, 53.6, 51.2, 46.7, 44.1,

39.4, 34.0, 32.5, 26.3, 24.9, 23.4, 23.2, 21.1, 8.8; HRMS

(FAB): (M+H)⁺calcd: 1089.6124, recorded: 1089.6123.

1

1160 cm ¹; H NMR (CDCl₃, 300 MHz) 7.33±7.27 (m,

1H), 7.06±6.67 (m, 7H), 5.79±5.75 (m, 1H), 5.31 (d,

J=6.5 Hz, 1H), 4.49 (s, 2H), 3.86 (s, 3H), 3.85 (s, 3H),

3.58±3.54 (m, 6H), 3.38 (d, J=12.4 Hz, 1H), 3.17 (td,

J=12.6, 2.7, 1H), 2.64±2.50 (m, 2H), 2.37 (d,

J=13.5 Hz, 1H), 2.30±2.18 (m, 1H), 2.10±2.00 (m, 1H),

1.79±1.36 (m, 7H), 1.22 (s, 3H), 1.21 (s, 3H), 0.88 (t,

J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 207.9,

169.7, 168.1, 167.3, 157.4, 148.9, 147.4, 141.9, 133.3,

130.0, 120.1, 114.3, 113.2, 111.7, 111.3, 76.6, 70.3, 69.7,

67.4, 55.9, 51.3, 46.7, 44.2, 38.8, 38.2, 32.5, 31.3, 26.4,

24.9, 23.5, 23.1, 21.2, 8.8; LRMS (ES+) (M+NH₄)⁺

1296, (M+Na)⁺1301; HRMS (FAB): (M+Na)⁺

calcd: 1301.6461, recorded: 1301.6510.

Dimer (1i). General procedure I was used for the

dimerization of 2d. The diamine 1,3-diaminopropane

replaces ethylenediamine as the coupling reagent. The

crude product was chromatographed (75% then 100%

EtOAc/hexane) to aord product (161 mg, 31%) as a

colorless foam: TLC (EtOAc/hexane, 3/1) R_f=0.33; IR

(neat) 3370, 2940, 1740, 1675, 1645, 1520, 1440,

1

1260 cm ¹; H NMR (CDCl₃, 300 MHz) 7.20±7.15 (m,

2H), 6.88±6.82 (m, 1H), 6.75 (dd, J=7.6, 2.1 Hz, 1H),

6.67±6.63 (m, 1H), 6.58±6.54 (m, 2H), 5.69±5.64 (m,

1H), 5.19 (d, J=6.3 Hz, 1H), 4.38 (s, 2H), 3.73 (s, 6H),

3.25±3.23 (m, 3H), 3.04 (t, J=12.8, 1H), 2.54±2.36 (m,

2H), 2.24 (d, J=12.9 Hz, 1H), 2.18±2.06 (m, 1H), 1.99±

1.89 (m, 1H), 1.62±1.49 (m, 6H), 1.42±1.12 (m, 2H), 1.10

(s, 6H), 0.76 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 208.3, 170.0, 169.0, 167.6, 157.8, 149.4, 147.8,

142.3, 133.8, 130.4, 120.6, 114.3, 114.0, 112.2, 111.8,

76.9, 67.6, 56.3, 51.7, 47.1, 44.5, 38.5, 35.9, 32.9, 31.6,

30.2, 26.8, 25.3, 23.9, 23.8, 21.5, 9.1; HRMS (FAB):

(M+Na)⁺calcd: 1227.6093, recorded: 1227.6102.

Dimer (1l). A solution of amine 18 (75 mg, 0.124 mmol)

in CH₂Cl₂(1.0 mL) at 0 ^ꢂC was treated with triethyl-

amine (35 mL, 0.248 mmol) followed by a solution of

CH₂Cl₂(100 mL) containing oxalyl chloride (4.9 mL,

0.1239 mmol). The reaction mixture was stirred for 2 h,

allowed to warm to room temperature, concentrated,

and chromatographed (75% then 100% EtOAc/hexane)

to aord product (21 mg, 32%) as a foam: TLC

(EtOAc) R_f=0.81; IR (neat) 3320, 2940, 140, 1680,

1

1645, 1515, 1260 cm

;

¹H NMR (CDCl₃, 300 MHz)

7.83 (t, J=5.5 Hz, 1H), 7.29±7.24 (m, 1H), 6.95±6.76 (m,

4H), 6.70±6.67 (m, 2H), 5.79±5.75 (m, 1H), 5.31 (d,

J=4.8 Hz, 1H), 4.11±4.08 (m, 2H), 3.86 (s, 3H), 3.85 (s,

3H), 3.76±3.71 (m, 2H), 3.37 (d, J=13.1 Hz, 1H), 3.17

(dd, J=12.7, 2.7 Hz, 1H), 2.65±2.47 (m, 2H), 2.37 (d,

J=13.9 Hz, 1H), 2.30±2.18 (m, 1H), 2.11±2.01 (m, 1H),

1.78±1.57 (m, 7H), 1.22 (s, 3H), 1.20 (s, 3H), 0.88 (t,

J=7.4 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 208.0,

170.1, 167.6, 160.2, 158.9, 149.3, 147.8, 141.9, 133.9,

130.2, 120.6, 119.9, 114.6, 113.3, 112.2, 111.8, 77.0, 66.5,

56.2, 51.7, 47.1, 44.6, 39.6, 38.4, 32.9, 31.6, 26.8, 25.4,

23.9, 23.5, 21.6, 9.1; LRMS (ES+): (M+NH₄)⁺1208,

(M+Na)⁺1213; HRMS (FAB): (M+Na)⁺calcd:

1213.5937, recorded: 1213.5903.

Dimer (1j). General procedure J was used for the

dimerization of 2d. The diamine 2,2⁰-oxybis(ethylamine)

dihydrochloride replaces ethylenediamine dihydro-

chloride as the coupling reagent. The crude product was

chromatographed (EtOAc) to aord product (1.86 g,

55%) as a colorless foam: TLC (EtOAc) R_f=0.26; IR

(neat) 3375, 2940, 1740, 1680, 1640, 1515, 1440, 1260,

1

1160, 1030 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.30±

7.25 (m, 1H), 7.00±6.90 (m, 3H), 6.83 (dd, J=8.2,

2.2 Hz, 1H), 6.78 (d, J=6.0 Hz, 1H), 6.76±6.66 (m, 2H),

5.79±5.75 (m, 1H), 5.30 (d, J=5.3 Hz, 1H), 4.49 (s, 2H),

3.85 (s, 3H), 3.84 (s, 3H), 3.54 (s, 4H), 3.37 (d,

1330

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

Dimer (1m). A solution of 18 (100 mg, 0.165 mmol) in

CH₂Cl₂(5.0 mL) at 0 ^ꢂC was treated with triethylamine

(46 mL, 0.331 mmol) followed by carbonyldiimidazole

(12 mg, 0.074 mmol), and allowed to warm to room

temperature and stir for 16 h. The organic layer was

then dried over Na₂SO₄, ®ltered, concentrated, and

chromatographed (75% then 100% EtOAc/hexane) to

(EtOAc) to aord product (94 mg, 75% from succini-

midyl ester) as a foam: TLC (EtOAc) R_f=0.30; IR

(neat) 3360, 2940, 1730, 1645, 1515, 1445, 1240, 1030,

1

760 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.32±7.29 (m,

2H), 7.18 (br s, 1H), 6.94±6.91 (m, 2H), 6.80 (d,

J=7.5 Hz, 1H), 6.76±6.65 (m, 2H), 5.77 (t, J=6.2 Hz,

1H), 5.28 (d, J=4.8 Hz, 1H), 4.48 (s, 2H), 3.86 (s, 3H),

3.85 (s, 3H), 3.55 (s, 2H), 3.35 (d, J=13.1 Hz, 1H), 3.11

(td, J=12.7, 2.8 Hz, 1H), 2.59±2.50 (m, 2H), 2.36±2.22

(m, 2H), 2.10±2.00 (m, 1H), 1.77±1.27 (m, 7H), 1.22 (s,

3H), 1.21 (s, 3H), 0.89 (t, J=7.4 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.2, 170.1, 169.5, 167.6, 157.4,

149.4, 147.8, 133.9, 133.8, 128.8, 122.1, 120.6, 115.2,

112.2, 111.8, 76.6, 67.6, 56.3, 56.3, 51.7, 47.1, 44.5,

39.8, 38.3, 32.9, 31.7, 26.8, 25.3, 23.9, 23.5, 21.6, 9.1;

HRMS (FAB): (M+Na)⁺calcd: 1213.5937, recorded:

1213.5914.

aord product (54 mg, 62%) as an oil: TLC (EtOAc)

1

R_f=0.55; IR (neat) 3380, 2940, 1740, 1645, 1515 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.27±7.21 (m, 1H), 6.92±

6.76 (m, 4H), 6.68±6.66 (m, 2H), 5.78±5.73 (m, 1H), 5.29

(d, J=4.8 Hz, 1H), 4.04 (br s, 2H), 3.85 (s, 3H), 3.84 (s,

3H), 3.58 (br s, 2H), 3.36 (d, J=13.0 Hz, 1H), 3.18 (td,

J=13.2, 3.1 Hz, 1H), 2.61±2.48 (m, 2H), 2.35 (d,

J=13.4 Hz, 1H), 2.30±2.17 (m, 1H), 2.11±2.02 (m, 1H),

1.78±1.64 (m, 5H), 1.61±1.41 (m, 2H), 1.21 (s, 3H), 1.91

(s, 3H), 0.87 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 208.3, 170.1, 167.8, 159.2, 149.3, 147.8, 141.9,

133.9, 130.1, 120.6, 119.5, 114.5, 113.4, 112.2, 111.8,

77.0, 68.0, 56.3, 51.7, 47.1, 44.5, 40.3, 38.4, 32.8, 31.7,

26.8, 25.3, 23.9, 23.5, 21.5, 9.2; LRMS (ES+):

(M+H)⁺1163, (M+NH₄)⁺1180; HRMS (FAB):

(M+Na)⁺calcd: 1185.5987, recorded: 1185.5973.

(R,R)-[2-[3-[3-(3,4-Dimethoxyphenyl)-1-hydroxypropyl]-

phenoxy]-1-[3-[3-(3,4-dimethoxyphenyl)-1-hydroxypropyl]-

phenoxymethyl]ethoxy]-dimethyl-(1,1-dimethylethyl)silane

(23). A solution of potassium tert-butoxide (216 mg,

1.92 mmol) in DMF (2.0 mL) was treated with phenol

4d (500 mg, 1.75 mmol) followed by epibromohydrin

(60 mL, 0.70 mmol) and heated at 100 ^ꢂC for 16 h. The

reaction mixture was then cooled and treated with

0.05 M pH 7 phosphate buer (10 mL) and EtOAc (10 mL).

The organic layer was washed with brine (3Â10 mL),

dried over Na₂SO₄, ®ltered, and concentrated to aord

a residue which was puri®ed by ¯ash chromatography

(50% then 75% EtOAc/hexane) to aord alcohol pro-

duct (210 mg, 48%; 56% based on recovery of 4d) as a

solid: TLC (EtOAc/hexane, 1/1) R_f=0.24; IR (neat)

3490, 2935, 1680, 1590, 1515, 1440, 1260, 1555,

Dimer (1n). A solution of aniline 20 (65 mg, 0.12 mmol)

in CH₂Cl₂(1.0 mL) at 0 ^ꢂC was treated with malonic

acid (6.5 mg, 0.06 mmol) and DIEA (108 mL, 0.62 mmol)

followed by BOP (82 mg, 0.19 mmol). The reaction

mixture was stirred at room temperature for 16 h after

which time the reaction was diluted with EtOAc

(20 mL), washed consecutively with a 1 N HCl solution

(2Â10 mL), a saturated aqueous NaHCO₃solution

(2Â10 mL), and brine (10 mL). The organic layer was

then dried over Na₂SO₄, ®ltered, concentrated, and

chromatographed (50% then 70% EtOAc/hexane) to

aord product (51 mg, 74%) as a white foam: TLC

1

1030 cm ¹; H NMR (CDCl₃, 300 MHz) 7.41±7.36 (m,

2H), 7.20 (t, J=8.0 Hz, 1H), 6.98 (dd, J=8.1, 2.3 Hz,

1H), 6.63±6.62 (m, 3H), 4.28±4.23 (m, 0.5 H), 4.09±4.02

(m, 2H), 3.70 (s, 3H), 3.69 (s, 3H), 3.10 (t, J=7.2 Hz,

2H), 2.85 (t, J=7.3 Hz, 2H), 2.66 (br s, 1H); ¹³C NMR

(CDCl₃, 75 MHz) 198.3, 157.9, 148.2, 146.7, 137.6,

133.1, 129.0, 120.5, 119.5, 119.1, 112.4, 111.2, 110.7,

68.2, 67.9, 55.2, 55.1, 40.0, 29.1; LRMS (ES+):

(M+H)⁺629, (M+NH₄)⁺649, (M+Na)⁺651;

(ES ): (M H) 627.

(EtOAc/hexane 2/1) R_f=0.34; IR (neat) 3329, 2938,

1

1737, 1698, 1641, 1515, 1443, 1262, 1029 cm

;

¹H

NMR (CDCl₃, 300 MHz) 9.39 (s, 2H), 7.66 (d,

J=7.9 Hz, 2H), 7.54 (s, 2H), 7.31 (t, J=7.8 Hz, 2H),

7.07 (d, J=7.4 Hz, 2H), 6.79±6.67 (m, 6H), 5.82 (t,

J=5.6 Hz, 2H), 5.34 (d, J=4.4 Hz, 2H), 3.85 (s, 6H),

3.84 (s, 6H), 3.55 (s, 2H), 3.36 (d, J=12.8 Hz, 2H), 3.12

(t, J=12.2, 2H), 2.61±2.52 (m, 4H), 2.36 (d, J=13.0 Hz,

2H), 2.27±2.04 (m, 6H), 1.76±1.62 (m, 10H), 1.48±1.41

(m, 4H), 1.24 (s, 6H), 1.23 (s, 6H), 0.90 (t, J=7.4 Hz,

6H); ¹³C NMR (CDCl₃, 75 MHz) 209.0, 169.9, 167.4,

165.8, 149.3, 147.8, 141.4, 138.4, 133.9, 129.7, 122.9,

120.6, 120.1, 118.2, 112.2, 111.8, 76.8, 56.3, 56.2,

51.6, 47.2, 44.6, 38.6, 32.9, 31.5, 26.6, 25.4, 23.8,

21.4, 9.1; HRMS (FAB): M⁺calcd: 1139.5569, recorded:

1139.5520.

A solution of the above alcohol (900 mg, 1.43 mmol) in

DMF (8.0 mL) was treated with tert-butyldimethylsilyl

chloride (324 mg, 2.15 mmol) followed by imidazole

(146 mg, 2.15 mmol). The reaction mixture was stirred

for 6 h then treated with EtOAc (20 mL) and water

(20 mL). The organic layer was washed with brine

(4Â50 mL) then dried over Na₂SO₄, ®ltered, con-

centrated, and ¯ash chromatographed (30% then 50%

EtOAc/hexane) to aord protected product (955 mg,

90%) as an oil: TLC (EtOAc/hexane, 2/3) R_f=0.38; IR

(neat) 2930, 1690, 1590, 1515, 1440, 1260, 1140,

Dimer (1s). General procedure J was used for the dimer-

ization of 22. Ethylenediamine was used as the coupling

reagent. The crude product was chromatographed

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1331

1

1030 cm ¹; H NMR (CDCl₃, 300 MHz) 7.40±7.35 (m,

(t, J=4.4 Hz, 2H), 3.92 (t, J=5.0 Hz, 2H), 3.84 (s, 6H),

2.73±2.54 (m, 2H), 2.13±1.91 (m, 2H); ¹³C NMR

(CDCl₃, 75 MHz) 159.4, 149.3, 147.6, 146.8, 134.8,

129.9, 120.6, 118.9, 114.0, 112.8, 112.3, 111.8, 74.1, 70.4,

67.9, 56.3, 56.2, 41.0, 32.0; LRMS (ES+): (M+NH₄)⁺

664, (M+Na)⁺669.

2H), 7.20 (t, J=8.1 Hz, 1H), 6.97 (dd, J=8.2, 2.0 Hz,

1H), 6.63 (s, 3H), 4.45±4.25 (m, 0.5H), 4.03±3.98 (m,

1H), 3.94±3.88 (m, 1H), 3.71 (s, 3H), 3.69 (s, 3H), 3.11

(t, J=7.4 Hz, 2H), 2.85 (t, J=7.3 Hz, 2H), 0.76 (s, 4.5

H), 0.00 (s, 3H); ¹³C NMR (CDCl₃, 75 MHz) 199.4,

159.4, 149.4, 147.9, 138.8, 134.3, 130.1, 121.3, 120.6,

120.4, 113.3, 112.4, 111.9, 70.3, 70.3, 56.3, 56.3, 41.2,

(R,R)-1,8-Bis[3-[3-(3,4-Dimethoxyphenyl)-1-hydroxypropyl]-

phenoxy]-3,6-dioxaoctane (25). General procedure M

was used for the alkylation of 4d. The halide 1,2-bis-(2-

iodoethoxy)ethane was used as the coupling reagent.

The crude product was chromatographed (50% then

75% EtOAc/hexane) to aord product (719 mg, 37%)

as a waxy solid: mp 90±91 ^ꢂC; TLC (EtOAc/hexane, 1/1)

30.3, 26.2,

4.2; LRMS (ES+): (M+H)⁺743,

(M+NH₄)⁺760, (M+Na)⁺765; (ES ): (M H) 741.

General procedure L was used for the reduction of the

above bis-ketone. The crude product was chromato-

graphed (30% then 50% EtOAc/hexane) to aord pro-

duct (618 mg, 73%) as an oil (>97% de by comparative

integration of ¹⁹F NMR resonances of the (+)MPTA

ester of chiral and racemic material): TLC (EtOAc/hex-

R_f=0.16; IR (neat) 2935, 1685, 1590, 1515, 1440, 1260,

1

1140, 1030 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.54±

7.50 (m, 2H), 7.34 (t, J=8.0 Hz, 1H), 7.11 (dd, J=7.6,

2.0 Hz, 1H), 6.82±6.76 (m, 3H), 4.16 (t, J=4.5 Hz, 2H),

3.89±3.82 (m, 8H), 3.76 (s, 2H), 3.25 (t, J=7.3 Hz, 2H),

3.00 (t, J=7.3 Hz, 2H); ¹³C NMR (CDCl₃, 75 MHz)

199.5, 159.4, 149.3, 147.8, 138.6, 134.3, 130.0, 121.2,

120.6, 120.4, 113.6, 112.3, 111.8, 71.3, 70.1, 68.0, 56.3,

56.2, 41.1, 30.2; LRMS(FAB): (M+H)⁺686

(M+Na)⁺709.

ane, 1/1) R_f=0.35; IR (neat) 3490, 2930, 1590, 1515,

;

¹H NMR (CDCl₃,

1

1445, 1260, 1140, 1030 cm

300 MHz) 7.11±7.07 (m, 1H), 6.77±6.72 (m, 2H), 6.69±

6.55 (m, 4H), 4.48 (dd, J=7.2, 5.5 Hz, 1H), 4.26±4.21

(m, 0.5H), 3.98±3.93 (m, 1H), 3.88±3.83 (m, 1H), 3.68 (s,

6H), 2.59±2.41 (m, 2H), 1.99±1.77 (m, 2H), 0.76 (s,

4.5H), 0.00 (s, 3H); ¹³C NMR (CDCl₃, 75 MHz) 158.0,

147.9, 146.3, 145.5, 133.5, 128.6, 119.3, 117.5, 112.7,

111.1, 110.9, 110.4, 72.8, 69.0, 68.8, 55.0, 54.9, 39.6,

30.7, 24.9, 4.2; LRMS (ES+): (M+Na)⁺769; (ES ):

(M H) 745.

General procedure L was used for the reduction of the

above bis-ketone. The crude product was chromato-

graphed (75% EtOAc/hexane) to aord product

(300 mg, 43%) as an oil (>95% de by comparative

integration of ¹⁹F NMR resonances of the (+)MPTA

ester of chiral and racemic material): TLC (EtOAc/hex-

(R,R)-1,5-Bis[3-[3-(3,4-Dimethoxyphenyl)-1-hydroxyprop-

yl]phenoxy]-3-oxapentane (24). General procedure M

was used for the alkylation of 4d. The halide bis(2-

iodoethyl) ether was used as the coupling reagent. The

crude product was chromatographed (40% then 50%

then 80% EtOAc/hexane) to aord product (6.76 g,

63%) as an oil: TLC (EtOAc/hexane, 1/1) R_f=0.28; IR

(neat) 2935, 1685, 1515, 1460, 1260, 1140, 1030 cm ¹; ¹H

NMR (CDCl₃, 300 MHz) 7.54±7.36 (m, 2H), 7.33 (t,

J=7.9 Hz, 1H), 7.11 (d, J=8.1 Hz, 1H), 6.81±6.77 (m,

3H), 4.19 (t, J=4.1 Hz, 2H), 3.94 (t, J=4.4 Hz, 2H),

3.86 (s, 3H), 3.84 (s, 3H), 2.45 (t, J=7.3 Hz, 2H), 3.00 (t,

J=7.5 Hz, 2H); ¹³C NMR (CDCl₃, 75 MHz) 199.6,

159.6, 149.5, 148.0, 138.8, 134.5, 130.1, 121.4, 120.8,

120.6, 113.8, 112.5, 112.0, 70.4, 68.3, 56.5, 56.4, 41.3,

30.4; LRMS (ES+): (M+H)⁺643, (M+Na)⁺665.

ane, 3/1) R_f=0.26; IR (neat) 3445, 2935, 1590, 1515,

1

1450, 1260, 1140, 1030 cm

;

¹H NMR (CDCl₃,

300 MHz) 7.09±7.02 (m, 1H), 6.75±6.71 (m, 2H), 6.65±

6.54 (m, 4H), 4.41 (dd, J=7.5, 5.4 Hz, 1H), 3.93 (t,

J=4.4 Hz, 2H), 3.68±3.66 (m, 8H), 3.56 (s, 2H), 2.55±

2.36 (m, 2H), 1.93±1.75 (m, 3H); ¹³C NMR (CDCl₃,

75 MHz) 159.4, 149.3, 147.6, 146.8, 134.8, 129.9, 120.6,

118.9, 114.0, 112.7, 112.2, 111.7, 74.1, 71.3, 70.2, 67.8,

56.3, 56.2, 41.0, 32.0; LRMS (FAB): (M+H)⁺690

(M+Na)⁺713.

(R,R)-1,11-Bis[3-[3-(3,4-Dimethoxyphenyl)-1-hydroxy-

propyl]phenoxy]-3,6,9-trioxaundecane (26). General pro-

cedure M was used for the alkylation of 4d. The halide

bis[2-(2-iodoethoxy)ethyl] ether was used as the cou-

pling reagent. The crude product was chromatographed

(70% then 80% EtOAc/hexane) to aord product

(5.05 g, 83%) as an oil: TLC (EtOAc/hexane, 3/1)

General procedure L was used for the reduction of the

above bis-ketone. The crude product was chromato-

graphed (50% then 80% EtOAc/hexane then EtOAc)

to aord product (1.25 g, 46%) as a waxy solid

(>95% de by comparative integration of ¹⁹F NMR

resonances of the (+)MPTA ester of chiral and racemic

material): mp 96±99 ^ꢂC; TLC (EtOAc/hexane, 3/1)

R_f=0.38; IR (neat) 2935, 1683, 1590, 1520, 1455, 1260,

1

1135, 1030 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.77±

7.71 (m, 2H), 7.56 (t, J=8.0 Hz, 1H), 7.35 (dd J=2.5,

0.6 Hz, 1H), 7.14±6.99 (m, 3H), 4.39 (t, J=4.6 Hz, 2H),

4.10 (s, 3H), 4.08 (s, 3H) 3.98±3.90 (m, 4H), 3.48 (t,

J=7.2 Hz, 2H), 3.23 (t, J=7.9 Hz, 2H); ¹³C NMR

(CDCl₃, 75 MHz) 199.5, 159.5, 149.3, 147.8, 138.6,

R_f=0.22; IR (neat) 3505, 2935, 1590, 1515, 1451, 1260,

1

1140, 1030 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.26±

7.20 (m, 1H), 6.92±6.70 (m, 6H), 4.64±4.60 (m, 1H), 4.15

1332

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

134.3, 130.0, 121.2, 120.6, 120.4, 113.6, 112.3, 111.8,

71.3, 71.1, 70.0, 68.0, 56.3, 41.2, 30.2; LRMS (ES+):

(M+H)⁺731, (M+NH₄)⁺648, (M+Na)⁺753.

diluted with EtOAc (50 mL). The organic extract was

then washed consecutively with a 1 N HCl solution

(2Â50 mL), a saturated aqueous NaHCO₃solution

(3Â50 mL), and brine (2Â50 mL). The organic layer was

dried over Na₂SO₄, ®ltered, concentrated, and puri®ed

by ¯ash chromatography (7.5% MeOH/EtOAc) to

aord product (4.45 g, 91%) as a solid: mp 123±

123.5 ^ꢂC; TLC (MeOH/CHCl3, 1/9) R_f=0.40; IR (neat)

General procedure L was used for the reduction of the

above bis-ketone. The crude product was chromato-

graphed (75% EtOAc/hexane then EtOAc) to aord

product (1.35 g, 28%) as an oil (>95% de by compara-

tive integration of ¹⁹F NMR resonances of the

(+)MPTA ester of chiral and racemic material): TLC

3355, 2935, 1670, 1590, 1515, 1440, 1260, 1155,

1

1030 cm

;

¹H NMR (CD₃OD, 300 MHz) 7.93 (br s,

(EtOAc) R_f=0.39; IR (neat) 3500, 2935, 1590, 1520,

;

¹H NMR (CDCl₃,

1H), 7.00 (t, J=7.8 Hz, 1H), 6.74±6.61 (m, 2H), 6.59±

6.44 (m, 4H), 4.35 (t, J=5.76 Hz, 1H), 4.20 (s, 2H), 3.54

(s, 3H), 3.53 (s, 3H), 3.19 (s, 2H), 2.49±2.26 (m, 2H),

1

1455, 1260, 1140, 1030 cm

300 MHz) 7.03 (t, J=8.0 Hz, 1H), 6.73±6.50 (m, 6H),

4.43 (dd J=7.4, 5.5 Hz, 1H), 3.91 (t, J=4.6 Hz, 2H),

3.64 (s, 6H), 3.50±3.48 (m, 4H), 2.48±2.39 (m, 2H),

1.89±1.76 (m, 3H); ¹³C NMR (CDCl₃, 75 MHz) 159.4,

149.3, 147.6, 146.8, 134.8, 129.9, 120.6, 118.8, 114.1,

112.7, 112.2, 111.7, 74.1, 71.2, 71.1, 70.2, 67.8, 56.3,

56.2, 41.0, 32.0; LRMS (ES+): (M+NH₄)⁺752,

(M+Na)⁺757.

1

1.78±1.68 (m, 2H); H NMR (CDCl₃, 300 MHz) 7.23±

7.14 (m, 2H), 6.94±6.92 (m, 2H), 6.77±6.69 (m, 4H), 4.62

(t, J=5.4 Hz, 1H), 4.33 (s, 2H), 3.82 (s, 6H), 3.45 (s,

2H), 3.04 (br s, 1H), 2.70±2.57 (m, 2H), 2.08±1.94 (m,

2H), ¹³C NMR (CD₃OD, 75 MHz) 172.3, 159.6, 150.7,

149.0, 136.8, 131.0, 122.1, 121.0, 115.0, 114.0, 113.7,

74.6, 68.6, 57.0, 56.9, 42.6, 40.4, 33.0; ¹³C NMR

(CDCl₃, 75 MHz) 169.6, 157.4, 148.9, 147.2, 147.1,

134.4, 129.7, 120.2, 119.8, 113.5, 112.4, 111.9, 111.4,

73.4, 67.1, 55.9, 55.8, 40.7, 39.1, 31.6; LRMS (ES+):

(M+H)⁺717, (M+Na)⁺739; HRMS (FAB):

(M+Na)⁺calcd: 739.3207, recorded: 739.3218.

(R)-[3-[3-(3,4-Dimethoxyphenyl)-1-hydroxypropyl]phen-

oxy]-acetic acid (27). A solution of 6d (4.4 g, 1.09 mmol)

in MeOH (20 mL) was treated with a solution of 6 N

NaOH (18.2 mL, 109 mmol) and allowed to stir for 14 h.

The reaction mixture was evaporated to half volume

and partitioned between water (20 mL) and ether

(25 mL). The aqueous portion was acidi®ed to pH 4

with a 1 N HCl solution and extracted with EtOAc

(2Â25 mL). The combined organic extracts were washed

brine (2Â25 mL), dried over Na₂SO₄, ®ltered, and con-

centrated to aord product (3.5 g, 92%) as an colorless

solid which may be recrystallized from EtOAc/hexane

(97% ee, +99% ee for recrystallized material, by Chir-

alcel OJ HPLC, 40% i-PrOH/hexane with 0.2% TFA,

retention time 14.0 min for the R-enantiomer and

11.5 min for the S-enantiomer): mp 124±125 ^ꢂC; TLC

(AcOH/MeOH/CHCl₃, 2/5/93) R_f=0.22; ¹H NMR

(CD₃OD, 300 MHz) 7.02 (t, J=8.1 Hz, 1H), 6.74±6.71

(m, 2H), 6.63±6.48 (m, 4H), 4.42 (s, 2H), 4.35 (t,

J=6.0 Hz, 1H), 3.57 (s, 3H), 3.56 (s, 3H), 2.46±2.28 (m,

2H), 1.85±1.67 (m, 2H); ¹³C NMR (CD₃OD, 75 MHz)

171.6, 158.5, 149.3, 147.6, 147.2, 135.3, 129.3, 120.6,

119.2, 113.3, 112.5, 112.4, 112.2, 73.1, 64.8, 55.5, 55.3,

41.0, 31.5; LRMS (ES+): (M+NH₄)⁺364, (M+Na)⁺

369; (ES ): M 345.

Dimer (1o). General procedure K was used for the cou-

pling of diol 23 with acid 14. The crude product was

chromatographed (30% EtOAc/hexane) to aord pro-

duct (125 mg, 44%) as an oil: TLC (EtOAc/hexane, 1/1)

R_f=0.65; IR (neat) 2930, 1740, 1700, 1645, 1515, 1450,

1

1450, 1260, 1140, 1030 cm

;

¹H NMR (CDCl₃,

300 MHz) 7.15±7.08 (m, 1H), 6.81±6.52 (m, 6H), 5.63 (t,

J=6.0 Hz, 1H), 5.17 (d, J=4.8 Hz, 1H), 4.28±4.24 (m,

0.5H), 4.09±3.96 (m, 1H), 3.94±3.84 (m, 1H), 3.70 (s,

3H), 3.69 (s, 3H), 3.21 (d, J=13.2 Hz, 1H), 3.00 (dd,

J=13.2, 3.0 Hz, 1H), 2.47±2.38 (m, 2H), 2.22 (d,

J=13.4 Hz, 1H), 2.16±2.01 (m, 1H), 1.95±1.89 (m, 1H),

1.65±1.11 (m, 7H), 1.08 (s, 3H), 1.05 (s, 3H), 0.78±0.70

(m, 7.5 H), 0.00 (s, 3H); ¹³C NMR (CDCl₃, 75 MHz)

208.1, 170.1, 167.6, 159.3, 149.3, 147.8, 141.9, 133.9,

130.1, 120.6, 119.5, 113.4, 112.2, 111.8, 70.4, 70.2, 56.3,

56.2, 51.7, 47.1, 44.6, 38.5, 32.9, 31.7, 26.2, 25.4, 23.9,

23.5, 21.6, 18.6, 9.1, 4.2; LRMS (ES+): (M+NH₄)⁺

1238.

A solution of the above silyl ether (55 mg, 0.450 mmol)

in CH₃CN (2.0 mL) was treated with a CH₃CN solution

(2.0 mL) containing 49% hydro¯uoric acid (40 mL). The

resulting solution was allowed to stir for 1 h then parti-

tioned between EtOAc (20 mL) and saturated aqueous

NaHCO₃solution (10 mL). The organic layer was

washed with an additional portion of aqueous NaHCO₃

solution (10 mL) followed by brine (2Â10 mL), then

dried over Na₂SO₄, ®ltered, concentrated, and ¯ash chro-

matographed (50% EtOAc/hexane) to aord product

(R,R)-1,10-Bis[3-[3-(3,4-dimethoxyphenyl)-1-hydroxypro-

pyl]phenoxy]-4,7-diaza-1,10-dioxa-3,8-dioxo-decane (28).

A solution of 27 (5.0 g, 14.4 mmol) in CH₂Cl₂(40 mL)

at 10 ^ꢂC was treated with PyBOP (7.51 g, 14.4 mmol)

followed by a CH₂Cl₂solution (10 mL) containing

ethylendiamine (507 mL, 7.58 mmol) and triethylamine

(4.05 mL, 28.9 mmol). The reaction mixture was warmed

to room temperature and stirred for 16 h after which

time the reaction was evaporated to half volume and

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

1333

(30 mg, 60%) as a colorless foam: TLC (EtOAc/hexane,

1/1) R_f=0.35; IR (neat) 2940, 1740, 1700, 1645, 1515,

1450, 1260, 1160, 1030 cm

Dimer (1r). General procedure K was used for the cou-

pling of diol 26 with acid 14. The crude product was

chromatographed (50% then 70% EtOAc/hexane) to

aord product (300 mg, 50%) as a colorless oil: TLC

1

;

¹H NMR (CDCl₃,

300 MHz) 7.23±7.17 (m, 1H), 6.88±6.60 (m, 6H), 5.71 (t,

J=6.2 Hz, 1H), 5.25 (d, J=4.8 Hz, 1H), 4.39±4.32 (m,

0.5 H), 4.17±4.09 (m, 2H), 3.78 (s, 3H), 3.77 (s, 3H), 3.28

(d, J=13.3 Hz, 1H), 3.08 (t, J=12.6 Hz, 1H), 2.87±2.80

(m, 1H), 2.58±2.45 (m, 2H), 2.29 (d, J=13.4 Hz, 1H),

2.23±2.11 (m, 1H), 2.04±1.95 (m, 5H), 1.70±1.20 (m,

2H), 1.14 (s, 3H), 1.13 (s, 3H), 0.81 (t, J=7.4 Hz, 1H);

¹³C NMR (CDCl₃, 75 MHz) 208.3, 170.1, 167.6, 159.1,

149.3, 147.8, 141.9, 133.9, 130.1, 120.6, 119.8, 114.6,

113.4, 112.2, 111.8, 77.0, 69.3, 69.1, 56.3, 56.3, 51.7,

47.1, 44.6, 38.5, 33.0, 31.6, 26.8, 25.4, 23.9, 23.6, 21.5,

9.1 LRMS (ES+): (M+NH₄)⁺1125, (M+Na)⁺1129;

HRMS (FAB): (M+Na)⁺calcd: 1129.5613, recorded:

1129.5652.

(EtOAc/hexane, 3/1) R_f=0.61; IR (neat) 2940, 1735,

1

1700, 1650, 1520, 1455, 1260, 1140, 1030 cm

;

¹H

NMR (CDCl₃, 300 MHz) 7.14 (t, J=4.2 Hz, 1H), 6.82±

6.55 (m, 7H), 5.66 (t, J=7.4 Hz, 1H), 5.20 (d J=4.7 Hz,

1H), 4.02 (t, J=4.3 Hz, 2H), 3.74 (s, 3H), 3.73 (s, 3H),

3.61±3.58 (m, 4H), 3.25 (d, J=12.8 Hz, 1H), 3.04 (td,

J=12.6, 2.9 Hz, 1H), 2.53±2.38 (m, 2H), 2.27±2.03 (m,

2H), 2.00±1.85 (m, 1H), 1.66±1.19 (m, 7H), 1.11 (s, 3H),

1.09 (s, 3H), 0.77 (t, J=7.5 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.2, 170.0, 167.3, 159.4, 149.3,

147.8, 141.7, 133.9, 130.0, 120.6, 119.5, 114.6, 113.6,

112.2, 111.8, 77.1, 71.2, 70.2, 67.9, 57.1, 56.2, 51.7, 47.1,

44.5, 38.4, 32.8, 31.6, 26.8, 25.3, 23.9, 23.5, 21.6, 9.1;

HRMS (FAB): (M+Na)⁺calcd: 1231.6294, recorded:

1231.6339.

Dimer (1p). General procedure K was used for the cou-

pling of diol 24 with acid 14. The crude product was

chromatographed (40% then 60% EtOAc/hexane) to

aord product (338 mg, 56%) as a colorless oil: TLC

(EtOAc/hexane, 1/1) R_f=0.20; IR (neat) 2940, 1735,

1700, 1650, 1520, 1455, 1260, 1140, 1030 cm ¹; ¹H NMR

(CDCl₃, 300 MHz) 7.22±7.18 (m, 1H), 6.90±6.62 (m, 6H),

5.73 (dd, J=7.6, 5.9 Hz, 1H), 5.26 (d, J=4.8 Hz, 1H),

4.19±4.11 (m, 2H), 3.97±3.88 (m, 2H), 3.81 (s, 6H), 3.14

(d, J=12.6 Hz, 1H), 3.11 (td, J=12.5, 2.8 Hz, 1H), 2.60±

2.42 (m, 2H), 2.31 (d, J=13.5 Hz, 1H), 2.26±2.16 (m,

1H), 2.14±1.97 (m, 1H), 1.73±1.26 (m, 7H), 1.07 (s, 3H),

1.06 (s, 3H), 0.84 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 208.2, 170.1, 167.6, 159.3, 149.3, 147.8, 141.7,

133.9, 130.1, 120.6, 119.5, 114.7, 113.5, 112.2, 111.8, 70.4,

67.9, 56.2, 51.7, 47.1, 44.5, 38.4, 32.9, 31.6, 26.8, 25.3,

23.9, 23.8, 21.6, 9.1; HRMS (FAB): (M+Na)⁺calcd:

1143.5769, recorded: 1143.5785.

(2S)-1-(3,3,-Dimethyl-1,2-dioxopentyl)-2-pyrrolidinecarb-

oxylic acid (29). Prepared from the methyl ester of l-

proline in an analogous manner to acid 14: mp 80.5±

81.5 ^ꢂC; TLC (MeOH/CHCl₃, 15/85) R_f=0.30; IR

1

(neat) 2970, 1700, 1640, 1455, 1180 cm

;

¹H NMR

(CDCl₃, 300 MHz) 11.36 (br s, 1H), 4.55 (dd, J=8.6,

4.2 Hz, 1H), 3.56±3.49 (m, 2H), 2.31±1.92 (m, 4H), 1.84±

1.65 (m, 2H), 1.25 (s, 3H), 1.22 (s, 3H), 0.87 (t,

J=7.5 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 206.7,

176.3, 165.6, 58.4, 47.4, 47.1, 32.2, 28.7, 24.8, 23.7, 23.2,

8.9; MS (ES+): (M+Na)⁺264; HRMS (FAB):

(M H) calcd: 240.1236, recorded: 240.1245.

(1R)-1-[3-(Carboxymethoxy)phenyl]-3-(3,4-dimethoxy-

phenyl)-1-propanyl

(2S)-1-(3,3-dimethyl-1,2-dioxo-

pentyl)-2-pyrrolidinecarboxylate (2h). General proce-

dure F was used for the coupling of 6d with 29. The

crude product was chromatographed (25% EtOAc/hex-

ane) to aord product (280 mg, 72%) as an oil: TLC

Dimer (1q). General procedure K was used for the cou-

pling of diol 25 with acid 14. The crude product was

chromatographed (50% then 70% EtOAc/hexane) to

aord product (70 mg, 41%) as a colorless oil: TLC

(EtOAc/hexane, 3/7) R_f=0.30; IR (neat) 2970, 1750,

1

1645, 1515, 1450, 1261, 1155 cm

;

¹H NMR (CDCl₃,

(EtOAc/hexane, 3/1) R_f=0.61; IR (neat) 2940, 1735,

1

300 MHz) 7.29±7.23 (m, 1H), 6.95±6.76 (m, 4H), 6.69±

6.65 (m, 2H), 5.76 (dd, J=7.8, 5.5 Hz, 1H), 4.59 (dd,

J=8.3, 3.6 Hz, 1H), 4.45 (s, 2H), 3.86 (s, 3H), 3.85 (s,

3H), 3.54 (dd, J=6.6, 4.4 Hz, 2H), 2.61±2.48 (m, 2H),

2.30±2.15 (m, 2H), 2.09±1.89 (m, 4H), 1.80±1.62 (m,

2H), 1.48 (s, 9H), 1.23 (s, 3H), 1.21 (s, 3H), 0.85 (t,

J=7.5 Hz, 3H); ¹³C NMR (CDCl₃, 75 MHz) 207.0,

170.7, 168.0, 165.1, 158.1, 148.9, 147.3, 141.6, 133.7,

129.6, 120.2, 119.7, 114.2, 112.9, 111.9, 111.4, 82.3, 76.1,

65.8, 59.8, 58.7, 55.9, 47.2, 46.9, 38.0, 38.7, 31.1, 29.0,

28.1, 24.9, 23.6, 23.3, 8.9; LRMS (ES+): (M+NH₄)⁺

643, (M+Na)⁺648.

1700, 1645, 1515, 1445, 1260, 1140, 1030 cm

;

¹H

NMR (CDCl₃, 300 MHz) 7.08±7.04 (m, 1H), 6.75±6.65

(m, 3H) 6.60±6.48 (m, 3H), 5.59 (t, J=6.1 Hz, 1H), 5.12

(d J=4.6 Hz, 1H), 3.95 (s, 2H), 3.67±3.66 (m, 8H), 3.57

(s, 2H), 3.17 (d, J=13.1 Hz, 1H), 2.97 (td, J=12.7,

2.7 Hz, 1H), 2.51±2.28 (m, 2H), 2.20±2.02 (m, 2H), 1.92±

1.83 (m, 1H), 1.59±1.41 (m, 4H), 1.36±1.12 (m, 2H), 1.04

(s, 3H), 1.02 (s, 3H), 0.70 (t, J=7.4 Hz, 3H); ¹³C NMR

(CDCl₃, 75 MHz) 208.2, 170.1, 167.6, 159.4, 149.3,

147.8, 141.7, 133.9, 130.0, 120.6, 119.5, 114.6, 113.6,

112.2, 111.8, 77.1, 71.3, 70.2, 67.8, 57.1, 56.3, 56.2, 51.7,

47.1, 44.5, 38.2, 32.9, 31.6, 26.8, 25.4, 23.8, 23.5, 21.6,

9.1; HRMS (FAB): (M+Na)⁺calcd: 1187.6033, recor-

ded: 1187.6089.

General procedure G was used for the acidolysis of the

above ester. The crude product was chromatographed

1334

T. Keenan et al./Bioorg. Med. Chem. 6 (1998) 1309±1335

(10% MeOH/CH₂Cl₂) to aord product (120 mg,

47%) as a foam: TLC (MeOH/CHCl₃, 15/85) R_f=0.25;

bound, compared to controls containing no competitor

(100%) and no protein (0%), and the concentration of

competitor resulting in 50% binding (IC₅₀) was deter-

mined by a non-linear least square ®t to a four-para-

meter equation.

1

IR (neat) 2940, 1735, 1700, 1635, 1455, 1210 cm

;

¹H NMR (CD₃OD, 30 MHz) 7.15 (t, J=8.0 Hz, 1H),

6.83±6.56 (m, 6H), 5.62±5.56 (m, 1H), 4.57 (s, 1H),

4.44±4.39 (m, 1H), 3.69 (s, 3H), 3.67 (s, 3H), 3.53±3.36

(m, 2H), 2.53±2.39 (m, 2H), 2.24±2.01 (m, 2H), 2.00±

1.77 (m, 4H), 1.66±1.45 (m, 2H), 1.11 (s, 3H), 1.10 (s,

3H), 0.74 (t, J=7.4 Hz, 3H); ¹³C NMR (CD₃OD,

75 MHz) 206.8, 170.6, 165.3, 157.7, 148.9, 147.4,

141.9, 133.6, 129.8, 120.2, 119.8, 114.7, 111.9, 111.4,

76.6, 58.6, 56.0, 47.3, 46.9, 38.0, 32.2, 31.7, 29.1,

24.8, 23.7, 23.2, 8.9; LRMS (ES+): (M+Na)⁺592;

HRMS (FAB): (M+Na)⁺calcd: 592.2523, recorded:

592.2507.

Assay for inducible Fas activation in cell lines. Inducible

Fas activation was assayed as previously described¹⁰In

brief, the human ®brosarcoma cell line HT1080 was

retrovirally transduced to express a chimeric construct

encoding a myristoylation sequence followed by two

FKBP domains then amino acids 175 to 304 of human

Fas. Cell line clones expressing this construct were pla-

ted at 10E4 cells/well in 96-well plates and treated the

next day with serial dilutions of compound, with 1 mM

usually the highest concentration tested. Wells were

assayed for viability one day later with the viability

indicator Alamar Blue (Accumed, Westlake, OH),

which measures reducing equivalents released during

cell metabolism. Untransfected HT1080 cells were tes-

tedalso and were unaected by the concentrations of

compounds used in these experiments.

Dimer (1h). General procedure K was used for the cou-

pling of diol 28 with acid 29. The crude product was

chromatographed (75% then 100% EtOAc/hexane) to

aord product (433 mg, 85%) as a foam: TLC (EtOAc)

R_f=0.20; IR (neat) 3360, 2965, 1740, 1675, 1640, 1515,

1

1440, 1260 cm

;

¹H NMR (CDCl₃, 300 MHz) 7.29±

7.26 (m, 1H), 6.95±6.90 (m, 2H), 6.84±6.76 (m, 2H),

6.69±6.66 (m, 2H), 5.77 (dd, J=7.6, 5.2 Hz, 1H), 4.59

(dd, J=8.3, 3.3 Hz, 1H), 4.44 (s, 2H), 3.86 (s, 3H), 3.84

(s, 3H), 3.49 (br s, 4H), 2.62±2.49 (m, 2H), 2.32±2.15 (m,

2H), 2.10±1.87 (m, 4H), 1.73±1.60 (m, 2H), 1.21 (s, 3H),

1.19 (s, 3H), 0.84 (t, J=7.4 Hz, 3H); ¹³C NMR (CDCl₃,

75 MHz) 207.0, 170.7, 169.3, 165.2, 157.4, 148.9, 147.4,

142.0, 133.6, 129.9, 120.2, 119.9, 114.2, 112.9, 111.9,

111.4, 76.0, 67.3, 59.8, 58.6, 56.0, 47.2, 46.9, 39.3, 38.2,

32.2, 31.1, 29.0, 24.9, 23.6, 23.3, 8.9; LRMS (ES+):

(M+H)⁺1163; HRMS (FAB): (M+Na)⁺calcd:

1185.5624, recorded: 1185.5635.

Assay for inducible transcriptional activation. Transcrip-

tion factor fusions were expressed from the tricistronic

vector pCGNN-F3p65/Z1F3/Neo.¹⁰An HT1080 (ATCC

CCL-121) cell line, HT1080L cells, which contain an

integrated secreted alkaline phosphatase (SEAP) target

gene under control of a minimal interleukin 2 gene pro-

moter and 12 ZFHD1 binding sites was generated as

described.²⁵Dimerizers were tested for their ability to

activate transcription of a target gene in (a) HT1080L

cells transiently transfected with pCGNN-F3p65/Z1F3/

Neo and (b) HT1080L cells in which the transcription

factor fusion proteins were expressed from a stably

integrated vector as described previously.¹⁰Following

incubation with compound for 18±24 h, the cell super-

natant was removed and assayed for SEAP activity.²⁵

Background SEAP activity, measured from mock-

transfected HT1080 cells, was subtracted from each

value.

Fluorescence polarization assay for FKBP12 binding.

The anities of synthetic ligands for FKBP12 were

determined using a competitive assay based on ¯uores-

cence polarization (FP). Full details of the assay will be

provided elsewhere (C.T. Rollins, E. Laborde, D. Holt

and T. Clackson, in preparation). Brie¯y, a ¯uorescent

probe was prepared by coupling 4⁰-(aminomethyl)-

¯uorescein (Molecular Probes) to the modi®ed allyl

group of FK506 in a manner similar to the preparation

of FK1012.¹Recombinant human FKBP12 was expres-

sed and puri®ed by standard methods.³³In the wells of a

Dynatech micro¯uor plate, subsaturating concentra-

tions of FKBP12 (11.25 nM) were incubated with

2.5 nM probe and serial dilutions of competitive ligand

in FP buer (50 mM potassium phosphate pH 7.8/

150 mM NaCl/100 mg/mL bovine gamma globulin/1%

EtOH). After equilibration for 30 min in the dark,

¯uorescence polarization was read on a Jolley FPM-2

(Jolley Consulting and Research, Inc., Grayslake, IL).

The increase in polarization of the probe upon binding

protein was used as a direct readout of percent probe

Acknowledgement

The authors thank Marcos Hatada for the determina-

tion of absolute stereochemistry of compound 27 by X-

ray crystallography.

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Article Doi

Synthesis and activity of bivalent FKBP12 ligands for the regulated dimerization of proteins

DOI: 10.1016/S0968-0896(98)00125-4

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Article abstract of DOI:10.1016/S0968-0896(98)00125-4

Full text of DOI:10.1016/S0968-0896(98)00125-4

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