Design and synthesis of simple macrocycles active against Vancomycin-resistant Enterococci (VRE)

DOI: 10.1002/chem.200600137

Design and Synthesis of Simple Macrocycles Active Against Vancomycin-

Resistant Enterococci (VRE)

Yanxing Jia,^[a]Nianchun Ma,^[a]Zuosheng Liu,^[a]Michle Bois-Choussy,^[a]

Eduardo Gonzalez-Zamora,^[b]Adriano Malabarba,^[c]Cristina Brunati,^[c]and

Jieping Zhu*^[a]

Abstract: 16-membered meta,para-cy-

clophanes mimicking the vancomycin

binding pocket (D–O–E ring) were de-

signed and synthesized. The structural

key features of these biaryl ether con-

taining macrocycles are (1) the pres-

ence of b-amino-a-hydroxy acid or a,b-

diamino acid as the C-terminal compo-

nent of the cyclopeptide and (2) the

presence of a hydrophobic chain or

lipidated aminoglucose at the appropri-

ate position. Cycloetherification by an

intramolecular nucleophilic aromatic

substitution reaction (S_NAr) is used as

the key step for the construction of the

macrocycle. The atropselectivity of this

ring-closure reaction is found to be

sensitive to the peptide backbone and

chemoselective cyclization (phenol

versus primary amine) is achievable.

Glycosylation of phenol was realized

with freshly prepared 3,4,6-tri-O-

acetyl-2-N-lauroyl-2-amino-2-deoxy-a-

hibitory concentrations for all of the

derivatives are measured by using a

standard microdilution assay, and

potent bioactivities against both sensi-

tive and resistant strains are found for

some of these compounds (MIC (mini-

mum

inhibitory

concentration)=

4 mgmL^À1against VRE). From these

preliminary SAR studies, it was antici-

pated that both the presence of a hy-

drophobic substituent and an appropri-

ate structure of the macrocycle were

required for this series of compounds

to be active against VRE.

d-glucopyranosyl

bromide

under

phase-transfer conditions. Minimum in-

Keywords: antibiotics

ether glycopeptides

cycles · S_NAr · vancomycin

·

biaryl

macro-

·

Introduction

used as a last resort for the treatment of infections due to

methicillin-resistant Staphylococcus aureus and other Gram-

positive organisms in patients allergic to b-lactam antibiot-

ics.^[1]Unfortunately, resistance to drugs of the vancomycin

family was recognized in the late 1980ꢀs and the frequency

of resistance has increased significantly over the past deca-

des, reaching 30% among hospitalized patients in 2002 in

the USA. As vancomycin-resistant enterococci (VRE) also

carry resistance to virtually all other known antibiotics, it

represents a serious threat to public health.^[2]

Staphylococcus aureus, a major cause of potentially life-

threating infections acquired in health care settings and in

the community, developed resistance to most classes of anti-

microbial agents soon after their introduction into clinical

use. As the prevalence of antibiotic resistance spread during

the 1980ꢀs, vancomycin became one of the fewantibiotics

[a] Y. Jia, N. Ma, Z. Liu, M. Bois-Choussy, Dr. J. Zhu

Institut de Chimie des Substances Naturelles

CNRS, 91198 Gif-sur-Yvette Cedex (France)

Fax : (+33)169-077-247

Vancomycin acts by binding to the terminal d-alanyl-d-

alanine (d-Ala-d-Ala) of the peptidoglycan precursors, thus

blocking the final stages of the peptidoglycan synthesis. Bac-

teria become resistant to vancomycin by reprogramming of

the peptidoglycan termini from d-Ala-d-Ala dipeptide to d-

Ala-d-Lac (d-alanyl-d-lactate) depsipeptide, which binds

only weakly to the drug.^[3]In fact, in vitro binding studies

have shown that the affinity of vancomycin for N-Ac-d-Ala-

d-Lac is about 1000 times less than its affinity for N-Ac-d-

Ala-d-Ala, due to one missing hydrogen bond and the

ground-state repulsion between the two oxygen lone-pairs in

the former complex. The reduced binding affinity translated

E-mail: zhu@icsn.cnrs-gif.fr

[b] Prof. E. Gonzalez-Zamora

Universidad Autónoma Metropolitana-Iztapalapa

San Rafael Atlixco 186, Col. Vicentina Iztapalapa

09340, D. F, Mexique (Mexico)

[c] Dr. A. Malabarba, Dr. C. Brunati

Vicuron Pharmaceuticals, Italy Research Center

via R. Lepetit, 34, 21040 Gerenzano (VA) (Italy)

Supporting information for this article is available on the WWW

under http://www.chemeurj.org/ or from the author.

5334

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

FULL PAPER

into about a 1000-fold reduced sensitivity of vancomycin-re-

sistant bacteria to this drug (Scheme 1).^[4,5]

Scheme 1. Hydrogen-bonded network of the complex vancomycin (1)

and N-Ac-d-Ala-d-Ala.

The emergence of vancomycin resistance provided an in-

centive for the discovery and development of newantibiot-

ics that would be active against both sensitive and resistant

strains of enterococci. One working direction has been the

search for newclasses of antibiotics and three drugs, namely

synercid,^[6]linezolid,^[7]and daptomycin,^[8]have been com-

mercialized so far. On the other hand, efforts dedicated to

the modification of natural glycopeptides to create new

semiACHTREUNGsynthetic derivatives were also fruitful. Extensive struc-

ture-activity relationship (SAR) studies performed by both

academic and industrial researchers indicated that the incor-

poration of a hydrophobic chain into the natural product is

highly beneficial for activities against VRE.^[9]Indeed both

oritavancin (LY333328)^[10]and dalbavancin,^[11]which entered

into late-stage clinical trials, contain a hydrophobic group.

The fact that a modification in the sugar part of vancomycin

and teicoplanin can reverse the drug-resistance is surprising,

as this subunit is not directly involved in substrate binding.

Indeed, in vitro activity of oritavancin did not parallel with

its binding affinity with d-Ala-d-Lac. Two theories have

been proposed to account for oritavancinꢀs bioactivity

against VRE.^[12]Williams hypothesized that the presence of

a lipid chain in the disaccharide part of vancomycin en-

hanced avidity for d-Ala-d-Lac by facilitating membrane an-

choring and/or by promoting dimerization.^[13]More recently,

Kahne advanced that oritavancin acts against VRE by direct

interaction with the transglycosylase without substrate bind-

ing^[14]and evidence that supports this viewhas been accu-

mulated.^[15,16]

Scheme 2. Generic structure of the modified carboxylate-binding pocket

of vancomycin.

CHOHCOR or CHNHCOR function can, a priori, lead to a

compound with increased affinity towards N-Ac-d-Ala-d-

Lac by restoring the missing hydrogen bond and by avoiding

the unfavorable electronic repulsion found in the vancomy-

cin/d-Ala-d-Lac complex.^[17]A hydrophobic chain will be in-

corporated at the appropriate position to direct the mole-

cule to interact with transglycosylase. In line with this work,

but with a different design principle, Ellman and co-workers

synthesized a combinatorial library of 16-membered macro-

cycles containing different tripeptide appendages at the C-

terminal and identified synthetic receptors that bind to the

N-Ac₂-l-Lys-d-Ala-d-Ala.^[18]On the other hand, Pieters and

co-workers have accomplished a solid-phase synthesis of the

Guided by these two hypotheses, we designed molecules

of a general structure (2, Scheme 2) in which the carboxy-

late-binding pocket of vancomycin is modified to keep the

required hydrogen-bonding network with the modified pep-

tidoglycan termini. We hypothesized that replacing the car-

bonyl group of AA4 (AA=amino acid) of vancomycin by a

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5335

J. Zhu et al.

C–O–D ring with different amino acid residues at the i+2-

position and studied their binding properties.^[19]It is worth

noting that structural modification of the vancomycin-type

glycopeptide is particularly challenging due to the molecular

complexity.^[20,21]Therefore, most of the chemical transforma-

tions reported to date have been localized on the periphery

of the macrocycles relying on simple chemical reactions.

Indeed, it would be extremely difficult, if it was not impossi-

ble, to reengineer the carboxylate-binding pocket (D–O–E

ring) of natural glycopeptides to include newhydrogen-

bond contacts with the modified peptidoglycan termini.^[22]

Therefore, the minimum structure required to carry the hy-

drophobic substituent remained unknown.^[22,23]

strate that both the structure of the macrocycle including

stereochemistry and the presence of a hydrophobic chain

are important for anti-VRE activity for this series of com-

pounds. We also document that the presence of a lipidated

aminosugar is not required if a lauroyl amide is incorporat-

ed at the appropriate position of the peptide backbone.

Compounds 2Be and 2Dc could serve as useful templates,

to a certain extent even more effectively than the entire gly-

copeptide framework, in searching for the active compounds

against both vancomycin-sensitive and -resistant strains.

Results and Discussion

In this paper, we report in detail the synthesis of the

modified carboxylate-binding pocket of vancomycin featur-

ing a key intramolecular S_NAr reaction according to the ret-

rosynthetic analysis depicted in Scheme 3.^[24,25]We demon-

Synthesis of the modified carboxylate-binding pocket con-

taining an external secondary hydroxy group: Synthesis of

the 16-membered macrocycles 3A and 3A’ was accomplish-

ed as depicted in Scheme 4. Coupling of l-phenylalanine

methyl ester (8) with l-N-Boc-4-fluoro-3-nitrophenyl ala-

nine (9)^[26](EDC, HOBt) afforded dipeptide 11 in 99%

yield. Removal of the Boc group under acidic conditions fol-

lowed by coupling with d-N-Boc-leucine (10) provided tri-

peptide 13, which was subsequently converted to its carbox-

ylic acid 14 upon hydrolysis (K₂CO₃, MeOH/H₂O). Coupling

of the suitably protected (2S,3R)-a-hydroxy-b-amino acid

15^[27]with tripeptide 14 (EDC, HOBt) afforded tetrapeptide

16 in excellent yield. Treatment of 16 with BCl₃led to the si-

multaneous deprotection of the isopropyl ether, the tert-bu-

tyldimethylsilyl ether, and the N-Boc function. Reintroduc-

tion of the Boc group furnished phenol 4A in 81% yield

over two steps.

The key intramolecular S_NAr-based cycloetherification of

4A was performed in DMSO (concentration of substrate=

0.01m) in the presence of CsF at room temperature. Two

separable atropisomers 3A and 3A’ were isolated in 72%

overall yield (ratio 3A/3A’ 3:1). The absolute configuration

of the planar chirality of 3A and 3A’ was deduced by NOE

studies.^[28]Thus, the NOE correlation between protons Ha/

Hb was observed in the NOESY spectrum of 3A, indicative

of the P configuration of this atropstereoisomer. On the

other hand, a Ha/Hc correlation, a characteristic of the M-

atropstereoisomer, was observed for compound 3A’.

The tetrapeptide 4B containing a (2R,3R)-a-hydroxy-b-

amino acid unit was synthesized by following the same syn-

thetic route as described for 4A. Interestingly, cyclization of

4B under identical conditions as described for 4A afforded

only one atropdiastereoisomer 3B in 65% yield (Scheme 5).

The high diastereoselectivity observed in the cycloetherifica-

tion of 4B relative to 4A was difficult to rationalize, but

was in accord with the previous observation that the atrop-

diastereoselectivity is highly substrate dependent.^{[20,24,29–31]}

From compounds 3A and 3A’, a series of derivatives

were synthesized (Scheme 6). Compound 2Aa was synthe-

sized in one step by heating a solution of 3A in MeCN/

conc. HCl (v/v 10:1, 408C). Under these conditions, both the

methyl ester and N-Boc functions were hydrolyzed to pro-

vide 2Aa in 86% yield. The synthesis of 2Ab containing a

Scheme 3. Retrosynthetic analysis of the modified carboxylate-binding

pocket of vancomycin. W=OH or NRR¹; X, Y=NO₂, NHCOR, or H;

R²=OH, OR, or NHR; R³, R⁴=H, alkyl, aryl, or amino sugar.

5336

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

lauroyl chloride to give, after chemoselective saponification,

the N-acylated compound 18 in 45% yield. Saponification

of the methyl ester (K₂CO₃, MeOH/H₂O) followed by re-

moval of the N-Boc function (conc. HCl in MeCN, v/v 10:1,

RT) provided compound 2Ab in 85% yield. Compound

2Ab was synthesized in order to study the hydrophobic

effect on the biological activity of this series of compounds.

Williams and co-workers have shown, by elegant NMR

spectroscopic studies, that vancomycin, ristocetin A, and

eremomycin among others exist in solution as homo-dimers

arranged in an antiparallel (head-to-tail) fashion.^[13,32]This

important observation has naturally provided incentive for

the synthesis of covalently linked glycopeptide dimers.^[33,34]

To exploit the potential polyvalent interaction, dimers 2Al

and Am were prepared (Scheme 8). Saponification of com-

pound 3A (K₂CO₃, MeOH/H₂O) afforded the correspond-

ing carboxylic acid 20 in quantitative yield. On the other

hand, removal of the Boc group of compound 3A to obtain

2Ae was found to be more difficult than one may expect

due to the lability of the methyl ester under aqueous acidic

conditions. After considerable experimental trials, 2Ae was

finally obtained in quantitative yield by treatment of its

methanol solution with thionyl chloride. Coupling of 2Ae

with N-Boc-3-amino propionic acid followed by chemoselec-

tive saponification of the aryl ester afforded 21. N-deprotec-

tion under mild acidic conditions followed by coupling with

20 provided the head-to-tail dimer 23 in 41% yield. Saponi-

fication of the methyl ester (LiOH, THF/H₂O) followed by

acidic treatment (HCl in MeCN, RT) afforded the desired

compound 2Al in 79% yield. Dimer 2Am linked by 6-

amino caproic acid was synthesized in a similar fashion via

intermediate 22.

The synthesis of compound 2Aj containing an N-acylated

aminoglucose unit was subsequently developed (Scheme 9).

The commercially available aminoglucose 25 was trans-

formed to glycosyl donor 28 in three steps. N-acylation of 25

with lauroyl chloride under Schotten–Baumann conditions

(C₁₁H₂₃COCl, H₂O/dioxane, aqueous NaHCO₃), followed by

O-acetylation gave the per-acylated compound 27. Bromina-

tion of 27 was best performed with a solution of HBr in

acetic acid^[35]to afford 3,4,6-tri-O-acetyl-2-N-lauroyl-2-

amino-2-deoxy-a-d-glucopyranosyl bromide (28). This com-

pound was stable only in solution and readily decomposed

upon evaporation to dryness. Consequently after the usual

workup, the organic extracts were used in the next step

without further purification. Koenigs-Knorr reaction^[36]of

freshly prepared 28 with 3A under phase-transfer conditions

(10% aqueous Na₂CO₃, nBu₄NHSO₄, CH₂Cl₂, RT)^[37]afford-

ed the desired b-glucoside 29 as the only isolable stereo-

isomer in 76% yield. The neighboring-group participation

(N-acyl) may explain the observed high b-selectivity. Finally,

hydrolysis of acetate and methyl ester under basic condi-

tions (LiOH, THF, H₂O) furnished acid 30 in 62% yield. N-

deprotection of 30 under acidic conditions provided 2Aj in

57% yield.

Scheme 4. Synthesis of 16-membered macrocycles 3A and 3A’: a) EDC,

HOBt, CH₂Cl₂, 258C, 12 h, 99%; b) conc. HCl, CH₃CN, 258C, 1.5 h; c) d-

N-Boc leucine (10), EDC, HOBt, CH₂Cl₂, 258C, 12 h, 76% (2 steps);

d) K₂CO₃, MeOH/H₂O 10:1, 258C, 36 h, 96%; e) EDC, HOBt, CH₂Cl₂,

258C, 12 h, 89%; f) (i) BCl₃, CH₂Cl₂, 08C, 1 h; then MeOH. (ii) Boc₂O,

NaHCO₃, dioxane/H₂O 2:1, 258C, 12 h, 81% (2 steps); g) CsF, DMSO,

258C, 16 h, 72%. Boc=tert-butoxycarbonyl; EDC=N-(3-dimethylamino-

propyl)-N’-ethylcarbodiimide hydrochloride; HOBt=1-hydroxybenzo-

triazole.

hydrophobic chain is summarized in Scheme 7. Hydrogena-

tion of the nitro group (H₂, 1 atm, Pd/C, MeOH) afforded

aniline 17, which was directly acylated with an excess of

It is noteworthy that 2-acyl-2-amino-2-deoxy-a-d-gluco-

pyranosyl bromide is known to be unstable and readily un-

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5337

J. Zhu et al.

infra), and should find applica-

tion in the synthesis of related

glycosides.

Compounds 2Ac, Ad, Ag,

and Ah were prepared from

3A’ following the chemistry de-

veloped for the synthesis of

2Aa, Ab, Ae, and Af. Com-

pounds synthesized from 3B

are listed in Scheme 10.

Scheme 5. Synthesis of 16-membered macrocycle 3B: a) CsF, DMSO, 258C, 16 h, 65%.

Scheme 11 summarizes the

synthesis of 2Bd. Reaction of

3B with 4-fluoro nitrobenzene

(DMSO, CsF, RT) afforded aryl

ether 31. Subsequent treatment

under

push-pull

conditions

(AlCl₃, EtSH, CH₂Cl₂) provided

a mixture of amino acid 32 and

amino ester 33, the ratio of

which was found to be time-de-

pendent. However, 32 can be

converted quantitatively to 33

under

standard

conditions

(SOCl₂, MeOH). N-tert-butoxy-

carbonylation of 33 provided

34, which was glycosylated to

35. Saponification followed by

acidic treatment afforded the

desired compound 2Bd in good

overall yield.

Compound 2Bf was designed

in the hope of introducing an

additional hydrogen bond with

the

peptidoglycan

termini

(Scheme 12). Reaction of 3B

with freshly prepared 3,4,6-tri-

O-acetyl-2-N-lauroyl-2-amino-2-

deoxy-a-d-glucopyranosyl bro-

mide (28) under phase-transfer

conditions

(10%

aqueous

Na₂CO₃, nBu₄NHSO₄, CH₂Cl₂,

RT) afforded 36 in 72% yield.

Hydrolysis of the methyl ester

under basic conditions (LiOH,

THF/H₂O) removed the acetate

function and provided the hy-

droxy acid 37. Coupling of 37

with amine 38 (EDC, HOBt,

CH₂Cl₂) provided 39, which

upon N-deprotection afforded

the desired compound 2Bf in

75% yield.

Scheme 6. Structures of macrocycles 2Aa–Am.

dergoes the acyl migration probably via the oxazoline and

ortho ester intermediates.^[38,39]Thus we would like to stress

that the procedure developed in the present study turned

out to be quite general and reliable (seven examples, vide

5338

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

epiACHTREmUNG erization as its enolization would not introduce addi-

tional strain into the already strained macrocycle, in contrast

to the enolization of internal amides of the macrocycle. Fur-

thermore, in the absence of this external amide function, the

macrocycle was found to be configurationally stable under

saponification conditions as observed in the 2A and 2B

series.

Starting from compounds 3D and by taking advantage of

this facile epimerization process, compounds 2Ca–Ce and

2 Da–Do were synthesized. Their structures are shown in

Schemes 15 and 16, respectively.

Compound 2De was obtained by thermal atropisomeriza-

tion of 42b (1508C, DMSO, 1:1 ratio) subsequent saponifi-

cation, and N-Boc deprotection. Compound 2Dg, incorpo-

rating a l-asparagine unit at the i+2-position, and the de-

sleucyl derivative 2Di were synthesized by following the

same synthetic strategy as described for 3D. Compound

2Df, devoid of planar chirality, was synthesized as shown in

Scheme 17. Thus, acylation of 3D with lauroyl chloride

under Schotten–Baumann conditions afforded compound

45. Catalytic hydrogenation of the nitro group (Pd/C,

MeOH, H₂) provided the aniline intermediate, which was

reductively deaminated (tBuONO, DMF, 758C) to give com-

pound 46. The latter compound was then transformed into

2Df by following a conventional two-step sequence.

Scheme 7. Synthesis of compound 2Ab: a) 10% Pd/C, H₂, MeOH, 258C,

2 h; b) lauroyl chloride, Et₃N, CH₂Cl₂, 258C, 4 h; c) K₂CO₃, MeOH/H₂O

10:1, 258C, 20 min, 45% (3 steps); d) K₂CO₃, MeOH/H₂O 10:1, 258C,

20 h; e) conc. HCl, CH₃CN, 258C, 2 h, 85% (2 steps).

Synthesis of the modified carboxylate-binding pocket of

vancomycin containing an external secondary amide group:

The synthesis of parent macrocycle 3D incorporating an

a,b-diamino acid at the C-terminal is shown in Scheme 13.

Coupling of tripeptide 14 with azido amine 7 (EDC, HOBt)

provided tetrapeptide 40, which was converted into com-

pound 41 as described for 4A. Cyclization of azido deriva-

tive 41 under a set of conditions which varied the bases

(CsF, K₂CO₃, Cs₂CO₃), temperature, and solvent (DMF,

DMSO, THF) failed to produce the desired 16-membered

macrocycle. We then turned our attention to amino com-

pound 4D which was obtained by reduction of the azide

group under Staudinger conditions (Ph₃P, THF, H₂O). Grati-

fyingly, cycloetherification of 4D (CsF, DMF) proceeded

smoothly to provide a single atropisomer 3D, the planar

chirality of which was deduced from detailed NMR spectro-

scopic studies. Interestingly, the formation of 14-member

para-cyclophane resulting from the nucleophilic addition of

primary amine onto the fluoro-aromatic ring system was not

observed under these conditions.^[40]

A facile racemization process was discovered serendipi-

tously during the course of this study (Scheme 14). Thus,

saponification of methyl ester 42a (R=Me) in THF/H₂O

with lithium hydroxide at 08C provided the desired carbox-

ylic acid 43a in almost quantitative yield. However, when

the same reaction was performed at room temperature, a

second product 44a was isolated. A control experiment indi-

cated that 43a and 44a were in equilibrium and a ratio of 1/

1.5 was obtained after prolonged stirring at room tempera-

ture. The structure of 44a was deduced to be a C_a-epimer. It

is indeed reasonable to suppose that C_ais more prone to

Antibiotic activity evaluation: Minimum inhibitory concen-

trations for these compounds and reference compounds

(vancomycin, teicoplanin, synercid^ꢂ, and daptomycin) are

measured by using a standard microdilution assay. The se-

lected results are summarized in Table 1

Compounds 2Aa–Am containing an external S-configured

secondary hydroxy group were found to be inactive against

both vancomycin-sensitive and resistant strains, regardless of

the absolute configuration of the planar chirality (2Aa

and Ab versus 2 A c and Ad) of the cyclophane. The intro-

duction of a hydrophobic chain at the E-ring (2Ab versus

2Aa, 2Ad versus 2Ac), a lipidated aminoglucose at the D-

ring (2Aj), or dimerization (2Ak–m) did not lead to the

active compounds.

On the other hand, compounds derived from 3B with an

external R-configured secondary hydroxy group displayed

interesting bioactivities. The parent compound 2Ba was in-

active, but its O-arylated derivatives 2Bb and Bc were able

to inhibit the growth of E faecalis Van A at reasonably low

MIC values (Table 1, entries 3 and 4). More interestingly, O-

glycosylated derivatives 2Bd and especially 2Be displayed

potent activities against VRE (entries 5 and 6). Further-

more, compound 2Bf containing an elongated peptide chain

at the C-terminal was active not only against VRE, but also

against

vancomycin-sensitive

Staphylococcus

aureus

(entry 7).

The activity of compounds 2Ca–Ce and 2 Da–Do contain-

ing an a,b-diamino acid at the C-terminal was found to be

less dependent on the stereochemistry of the C_a-carbon in

contrast to the OH-series. However, the functionalization of

the C_a-amino group has a large impact on the bioactivity of

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5339

J. Zhu et al.

(entry 22) containing an elon-

gated peptide chain at the C-

terminal is active against

a

broad spectrum of both vanco-

mycin-sensitive (Staphylococcus

aureus) and resistant strains.

It is noteworthy that some of

the macrocycles reported in this

paper are more active, in vitro,

against VRE than most of the

vancomycin and teicoplanin de-

rivatives reported in the litera-

ture and are almost as active as

synercid^ꢂ, a clinically used drug

for combating VRE. The gener-

ic structure 2 was originally de-

signed with the hope of restor-

ing the missing hydrogen bond

with the d-Ala-d-Lac depsipep-

tide by switching the amide car-

bonyl (hydrogen-bond accept-

or) of vancomcyinꢀs fourth

amino acid into

a hydroxy

group (hydrogen-bond donor).

Although interesting activities

against VRE were indeed

found for some of these deriva-

tives, substrate binding cannot

account for their antibiotic ac-

tivities for the following rea-

sons: (1) attempts to measure

the binding affinity between

2Be and N-Ac-d-Ala-d-Ala as

well as 2Be and N-Ac-d-Ala-d-

Lac by either UV absorption

techniques or by NMR titration

(in DMSO) failed to provide

any exploitable results, most

probably due to the lowrecep-

Scheme 8. Synthesis of head-to-tail dimers 2Al and Am: a) K₂CO₃, MeOH/H₂O 10:1, 258C, 24 h, 100%;

b) SOCl₂, MeOH, 258C, 1 h; c) N-Boc-3-amino propionic acid or N-Boc-6-amino caproic acid, EDC, HOBt,

Et₃N, CH₂Cl₂, 258C, 12 h; d) K₂CO₃, MeOH/H₂O 10:1, 258C, 20 min, 60% (3 steps); e) (i) SOCl₂, MeOH,

258C, 1 h; (ii) 20, EDC, HOBt, Et₃N, CH₂Cl₂, 258C, 12 h; (iii) K₂CO₃, MeOH/H₂O 10:1, 258C, 20 min, 41%

(3 steps); f) (i) LiOH, THF/H₂O 3:1, 08C, 4 h; (ii) conc. HCl, CH₃CN, 258C, 2 h, 79%.

these compounds. Thus, neither the parent compounds 2Da,

its N,N-dimethylated derivative 2Db, or the N-acetyl deriva-

tives 2Ca and 2Dh were active against VRE. On the other

hand, the lauroyl (N-dodecanoyl) amides 2Cc and 2Dc pro-

duced interesting activities against VRE (entries 9 and 13),

indicating the important role of a hydrophobic chain. Com-

pound 2Dg (entry 17), containing an asparagine unit instead

of a phenylalanine in the i+2-position, was slightly less

active than 2Dc (entry 13). Planar chirality plays only a

minor effect on the bioactivity as the potency of 2Dc

and De are comparable (entry 15). However, the presence

of the nitro group at the E ring is beneficial as 2Df, devoid

of this group was much less active (entry 16). The activity

against VRE remained essentially unchanged upon benzyla-

tion and glucosylation of the phenol function. Although

2Ce missing the leucine-terminal is inactive, reasonable ac-

tivities against VRE remained for des-leucyl derivative 2Di

(entry 19). As in the case of the OH series, compound 2Do

tor-substrate affinities, (2) although 2Ce was inactive, 2Di

with a damaged binding pocket was able to inhibit the

growth of Enterococcus faecalis Van A at a reasonably low

MIC value, and (3) the observed hydrophobic effect is appa-

rently not due to the simple increase of effective molarity

resulting from membrane anchoring. Rather it was specific,

as no beneficial effect was observed when the same aliphatic

chain was introduced to E-ring of the molecule (2Ab

and Ad). This result can be better explained on the basis of

a specific interaction between the macrocycle and the target

enzymes. Overall, and in accord with Kahneꢀs observa-

[16]

tion,^[14]

,

we hypothesize that these compounds might have

a direct interaction with proteins critical for VRE cell-wall

biosynthesis, although a detailed mechanism of action re-

mains to be investigated.

5340

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

Scheme 9. Synthesis of glycosylated macrocycle 2Aj: a) lauroyl chloride,

NaHCO₃, dioxane/H₂O 1:1, 08C, 4 h, 61%; b) Ac₂O, pyridine, 08C, 4 h,

94%; c) 30% HBr in HOAc, HOAc, 258C, 3 h; d) 3 A, (nBu)₄NHSO₄,

10% aqueous Na₂CO₃/CH₂Cl₂(1:1), 258C, 4 h, 76%; e) LiOH, THF/H₂O

3:1, 08C, 4 h, 62%; f) conc. HCl, CH₃CN, 258C, 2 h, 57 %.

Conclusion

A modified vancomycin-binding pocket (D–O–E ring) has

been designed and synthesized. The structural key features

of this biaryl ether containing macrocycle are (1) the incor-

poration of b-amino-a-hydroxy acid or a,b-diamino acid as

the C-terminal component of the cyclopeptide and (2) the

presence of a hydrophobic chain or lipidated aminoglucose

at the appropriate position. Cycloetherification by an intra-

molecular nucleophilic aromatic substitution reaction

(S_NAr) is used as the key step for the construction of the

macrocycle. We demonstrated in the present study that a

combination of a modified binding pocket with a suitably

positioned hydrophobic chain constitutes a viable approach

in the search for compounds active against VRE. Further-

more, the presence of a lipidated aminosugar is not required

if a lauroyl amide is incorporated at the appropriate position

of the peptide backbone. Although substrate binding may

not be the determinant factor for the anti-VRE activities of

these compounds, we assume from these preliminary struc-

ture-activity relationship studies that the structure of the

macrocycle is important for the observed activities and even

a subtle change of one chiral center can perturb the potency

of a given compound. Such an observation is of course un-

derstandable, if the enzyme-substrate interaction is consid-

ered to be the major mechanism of action of these cyclo-

phanes.

Scheme 10. Structures of macrocycles 2Ba–Bf.

Experimental Section

Compound 11: HOBt (1.44 g, 10.7 mmol) and EDC (2.39 g, 12.5 mmol)

were added to a solution of amine 8 (1.75 g, 9.8 mmol) and acid 9 (2.92 g,

8.9 mmol) in CH₂Cl₂(100 mL). The reaction mixture was stirred at room

temperature for 12 h and then diluted with CH₂Cl₂(100 mL). The result-

ing mixture was washed with 5% aqueous HCl, saturated NaHCO₃, H₂O,

brine, dried over Na₂SO₄, and concentrated under vacuum. The residue

was purified by flash-column chromatography (silica gel, heptane/EtOAc

5:1) to afford 11 (4.31 g, 99%). M.p. 45–478C; [a]_D=À8.9 (c=0.15 in

MeOH); ¹H NMR (200 MHz, CDCl₃): d=7.81 (d, J=6.9 Hz, 1H; ArH),

7.40–7.00 (m, 7H; ArH), 6.59 (d, J=7.7 Hz, 1H; NH), 5.00 (d, J=8.6 Hz,

1H; NH), 4.81 (dd, J=7.7, 6.7 Hz, 1H; CH), 4.39 (m, 1H; CH), 3.73 (s,

3H; CO₂CH₃), 3.19–2.87 (m, 4H; 2CH₂), 1.38 ppm (s, 9H; C

ACHTREUNG(CH₃)₃);

¹³C NMR (50.3 MHz, CDCl₃): d=171.4, 170.1, 154.8, 153.9 (J=262 Hz),

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5341

J. Zhu et al.

Scheme 11. Synthesis of glycosylated macrocycle 2Bd: a) 1-fluoro-4-nitrobenzene, CsF, DMSO, 258C, 2 h, 100%; b) AlCl₃, EtSH, CH₂Cl₂, 08C, 2.5 h,

53%; c) SOCl₂, MeOH, 608C, 12 h; d) Boc₂O, NaHCO₃, dioxane/H₂O 2:1, 258C, 2 days, 60%; e) 28, (nBu)₄NHSO₄, 10% aqueous Na₂CO₃/CH₂Cl₂1:1,

258C, 4 h, 73%; f) LiOH, THF/H₂O 3:1, 08C, 1.5 h; g) TFA, CH₂Cl₂, 08C, 1 h, 79% (2 steps).

Scheme 13. Synthesis of macrocycle 3D: a) EDC, HOBt, CH₂Cl₂, 258C,

12 h, 93%; b) (i) BCl₃, CH₂Cl₂, 08C, 1 h; then MeOH; (ii) Boc₂O,

NaHCO₃, dioxane/H₂O 2:1, 258C, 12 h, 95% (2 steps); c) Ph₃P, H₂O,

THF, 258C, 12 h, 77%; d) CsF, DMSO, 258C, 16 h, 85%.

Scheme 12. Synthesis of C-terminal elongated macrocycle 2Bf: a) 28,

(nBu)₄NHSO₄, 10% aqueous Na₂CO₃/CH₂Cl₂1:1, 258C, 4 h, 76%;

b) LiOH, THF/H₂O 3:1, 08C, 4 h, 62%; c) 38, EDC, HOBt, CH₂Cl₂,

258C, 12 h, 34%; d) TFA, CH₂Cl₂, 08C, 1 h, 75%.

5342

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

Scheme 14. Facile epimerization of macrocycle 42: a) LiOH, THF/H₂O, 0 8C, 43/44 1:0; b) LiOH, THF-H₂O, RT, 43/44 1:1.5.

trated under vacuum. The residue was purified by flash-column chroma-

tography (silica gel, CH₂Cl₂/MeOH 100:1) to afford 13 (5.0 g, 76%). M.p.

175–1778C; a_D=+15.3 (c=0.24 in MeOH); ¹H NMR (250 MHz,

CDCl₃): d=7.79 (dd, J=7.3, 2.3 Hz, 1H; ArH), 7.40–6.90 (m, 7H; ArH),

6.80–6.60 (m, 2H; 2NH), 4.80–4.60 (m, 3H; NH, 2CH), 3.99 (m, 1H;

CH), 3.70 (s, 3H; CO₂CH₃), 3.20–2.95 (m, 4H; 2CH₂), 1.70–1.40 (m,

3H; CH, CH₂), 1.41 (s, 9H; CACTHRE(UNG CH₃)₃), 0.91 (d, J=4.7 Hz, 3H; CH₃),

0.89 ppm (d, J=4.7 Hz, 3H; CH₃); ¹³C NMR (50.3 MHz, CDCl₃): d=

172.4, 171.2, 169.3, 155.4, 153.8 (J=254 Hz), 136.2, 136.0, 135.4, 132.9,

128.6, 128.1, 126.7, 126.2, 117.8 (J=21 Hz), 80.0, 53.1, 53.0, 52.7, 51.9,

40.3, 37.2, 36.2, 27.6, 24.2, 22.4, 21.0 ppm; IR (CHCl₃): n˜ =3667, 3427,

3030, 3010, 2961, 2934, 2873, 1742, 1691, 1675, 1621, 1540, 1499, 1439,

1369, 1353, 1253, 1161, 1047 cm^À1

; HRMS (ESI): m/z: calcd for

C₃₀H₃₉N₄O₈FNa: 625.2650 [M+Na]⁺; found: 625.2664.

Compound 14: K₂CO₃(552 mg, 4.0 mmol) was added to a solution of 13

(1.2 g, 2.0 mmol) in MeOH/H₂O (10:1, 55 mL). After the reaction mix-

ture had been stirred for 36 h at room temperature, it was concentrated

under vacuum. The resulting residue was acidified to pH 2–3 with 5%

aqueous HCl and extracted with EtOAc. The organic layer was washed

with H₂O, brine, dried over Na₂SO₄, and concentrated under vacuum.

The residue was purified by flash-column chromatography (silica gel,

CH₂Cl₂/MeOH 40:1–20:1) to afford 14 (1.13 g, 96%). M.p. 94–978C;

[a]_D=+25.4 (c=0.28 in MeOH); ¹H NMR (250 MHz, CDCl₃): d=7.83

(d, J=5.7 Hz, 1H; ArH), 7.42–6.90 (m, 8H; ArH, NH), 7.00 (m, 1H;

NH), 5.09 (d, J=6.6 Hz, 1H; NH), 4.92 (m, 1H; CH), 4.72 (m, 1H; CH),

4.08 (m, 1H; CH), 3.30–2.80 (m, 4H; 2CH₂), 1.39 (s, 9H; CACHTREUNG(CH₃)₃),

1.70–1.20 (m, 3H; CH, CH₂), 0.82 (d, J=3.3 Hz, 3H; CH₃), 0.80 ppm (d,

J=3.3 Hz, 3H; CH₃); ¹³C NMR (50.3 MHz, CDCl₃): d=175.9, 174.6,

172.5, 158.2, 155.9 (J=259 Hz), 138.8, 138.4, 138.2, 135.9, 130.7, 129.9,

128.2, 128.1, 119.5 (J=20 Hz), 81.1, 55.6, 55.2, 54.8, 42.5, 38.7, 38.3, 29.1,

26.2, 23.8, 22.2 ppm; IR (CHCl₃): n˜ =3686, 3431, 3374, 3034, 3011, 2961,

2934, 2873, 1666, 1540, 1500, 1455, 1369, 1352, 1253, 1162, 1017 cm^À1; MS

(EI): m/z: 587 [MÀH]⁺.

Compound 16: TBDSOTf (5.18 mL, 22.1 mmol) was added to a solution

of 5 (3.25 g, 7.37 mmol) and 2,6-lutidine (2.19 mL, 18.4 mmol) in CH₂Cl₂

(20 mL) over 30 min. After the reaction mixture had been stirred for

30 min, it was acidified with HCl (2N) to pH 2 and stirring continued for

an additional 30 min. The resulting reaction mixture was basified to

pH 7–8 with saturated NaHCO₃. The two phases were separated and the

aqueous phase was extracted with CH₂Cl₂. The combined organic layers

were washed with H₂O, brine, dried over Na₂SO₄, and concentrated

under vacuum to give the desired amine 15, which was of sufficient

purity for direct use in the next step. ¹H NMR (200 MHz, CD₃CN): d=

Scheme 15. Structures of macrocycles 2Ca–Ce.

136.1, 135.9, 135.2, 133.4, 128.6, 128.1, 126.7, 126.1, 117.7 (J=29 Hz),

79.9, 54.2, 52.8, 51.9, 37.2, 36.6, 27.6 ppm; IR (CHCl₃): n˜ =3425, 3032,

2983, 1742, 1683, 1622, 1540, 1497, 1352, 1253, 1163 cm^À1; HRMS (ESI):

m/z: calcd for C₂₄H₂₈N₃O₇FNa: 512.1809 [M+Na]⁺; found: 512.1813.

Compound 13: Concentrated HCl (6.0 mL) was added to a solution of 11

(5.13 g, 10.9 mmol) in CH₃CN (60 mL). After the reaction mixture had

been stirred for 1.5 h at room temperature, it was diluted with EtOAc

(100 mL), basified to pH 8–10 with saturated NaHCO₃, and then extract-

ed with EtOAc. The organic layer was washed with H₂O, brine, dried

over Na₂SO₄, and concentrated under vacuum to afford 12 which was

used directly for next reaction. HOBt (1.29 g, 9.6 mmol) and EDC

6.61 (s, 2H; ArH), 4.57 (m, 2H; CH

CH), 4.16 (d, J=3.8 Hz, 1H; CH), 3.68 (s, 3H; OCH₃), 3.66 (s, 3H;

CO₂CH₃), 1.31 (d, J=4.4 Hz, 6H; CH(CH₃)₂), 1.28 (d, J=4.2 Hz, 6H;

CH(CH₃)₂), 0.79 (s, 9H; Si

(CH₃)₃), À0.08 (s, 3H; SiCH₃), À0.23 ppm (s,

ACHTRE(UNG CH₃)₂), 4.32 (d, J=3.8 Hz, 1H;

AHCTREUNG

A

ACHTREUNG

3H; SiCH₃); MS (ESI): m/z: 456 [M+H]⁺. HOBt (1.12 g, 8.1 mmol) and

EDC (1.59 g, 8.1 mmol) were added to a solution of the above crude

amine 15 and acid 14 (5.21 g, 8.85 mmol) in CH₂Cl₂(80 mL). The reac-

tion mixture was stirred at room temperature for 12 h before it was dilut-

ed with CH₂Cl₂(100 mL). The resulting mixture was washed with 5%

aqueous HCl, saturated NaHCO₃, H₂O, brine, dried over Na₂SO₄, and

concentrated under vacuum. The residue was purified by flash-column

chromatography to afford 16 (6.7 g, 89%). M.p. 90–928C; [a]_D=+11.6

(2.33 g, 12.2 mmol) were added to

a solution of amine 12 (3.38 g,

8.7 mmol) and acid 10 (2.21 g, 9.6 mmol) in CH₂Cl₂(100 mL). The reac-

tion mixture was stirred at room temperature for 12 h and then diluted

with CH₂Cl₂(100 mL). The resulting mixture was washed with 5% aque-

ous HCl, saturated NaHCO₃, H₂O, brine, dried over Na₂SO₄, and concen-

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5343

J. Zhu et al.

Scheme 16. Structures of macrocycles 2 Da–Do.

(c=0.22 in MeOH); ¹H NMR (250 MHz, CDCl₃): d=7.73 (dd, J=7.0,

2.1 Hz, 1H; ArH), 7.30–7.14 (m, 7H; ArH), 7.12–7.10 (m, 2H; 2NH),

6.85 (d, J=8.3 Hz, 1H; NH), 6.44 (s, 2H; ArH), 5.26 (dd, J=8.8, 1.7 Hz,

1H; CH), 4.84 (d, J=6.6 Hz, 1H; NH), 4.80–4.64 (m, 2H; 2CH), 4.54–

4.44 (m, 2H; CHCAHTRE(UNG CH₃)₂), 4.22 (d, J=8.8 Hz, 1H; CH), 3.99 (m, 1H;

CH), 3.79 (s, 3H; OCH₃), 3.69 (s, 3H; CO₂CH₃), 3.30 (dd, J=13.6,

5.7 Hz, 1H; CH₂), 3.17 (dd, J=13.8, 6.0 Hz, 1H; CH₂), 3.02–2.86 (m, 2H;

CH₂), 1.64–1.34 (m, 3H; CH, CH₂), 1.42 (s, 9H; C

5.7 Hz, 6H; CH(CH₃)₂), 1.32 (d, J=5.7 Hz, 6H; CH

6.6 Hz, 3H; CH₃), 0.87 (d, J=6.6 Hz, 3H; CH₃), 0.76 (s, 9H; SiACHTREUNG

ACHTREUNG

A

ACHTREUNG

À0.16 (s, 3H; SiCH₃), À0.24 ppm (s, 3H; SiCH₃); ¹³C NMR (50.3 MHz,

CD₃OD): d=175.5, 173.5, 173.1, 172.5, 158.6, 156.0 (d, J=261 Hz), 153.3,

138.7, 138.4, 138.2, 135.9, 135.7, 130.8, 130.6, 130.0, 128.3, 128.2, 119.5 (d,

J=21 Hz), 109.9, 109.7, 81.0, 77.5, 73.2, 73.1, 61.4, 57.8, 56.3, 54.9, 53.3,

53.1, 42.5, 39.5, 38.7, 29.2, 26.7, 26.6, 26.2, 24.0, 23.9, 23.4, 23.2, 23.1, 23.0,

22.2, 19.6, À4.6, À5.0 ppm; IR (CHCl₃): n˜ =3676, 3420, 3022, 2957, 2933,

2859, 1746, 1683, 1590, 1497, 1369, 1352, 1254, 1212, 1139, 1116,

1006 cm^À1; HRMS (ESI): m/z: calcd for C₅₂H₇₆N₅O₁₃FSiNa: 1048.5091

[M+Na]⁺; found: 1048.5081.

Compound 4A: BCl₃(1m in CH₂Cl₂, 130 mL, 130 mmol) was added to a

solution of 16 (6.67 g, 6.50 mmol) in CH₂Cl₂(50 mL) at 08C. After the re-

action mixture had been stirred for 1 h at 08C, the reaction was quenched

by the slowaddition of anhydrous MeOH. The volatile was evaporated

Scheme 17. Synthesis of macrocycle 2Df: a) lauroyl chloride, NaHCO₃,

dioxane/H₂O 2:1, 08C, 4 h, 74%; b) (i) 10% Pd/C, H₂, MeOH, 258C,

30 min; (ii) tBuONO, DMF, 758C, 15 min, 52%; c) LiOH, THF/H₂O 3:1,

08C, 4 h, 52%; d) TFA, CH₂Cl₂, 258C, 30 min, 80%.

5344

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

Table 1. MICs [mgmL^À1] of selected macrocycles and reference compounds.^[a]

(872 mg, 72%). For compound 3A:

m.p. 135–1398C; [a]_D=À6.0 (c=0.20

in MeOH); ¹H NMR (200 MHz,

CD₃CN): d=8.19 (s, 1H; ArH), 7.37

(dd, J=8.4, 1.9 Hz, 1H; ArH), 7.30–

7.00 (m, 8H; ArH, 2NH), 6.62 (m,

1H; NH), 6.57 (s, 1H; ArH), 5.79 (m,

1H; NH), 5.50 (s, 1H; ArH), 5.05 (m,

1H; CH), 4.60–4.40 (m, 3H; 3CH),

4.16 (dd, J=7.6, 4.9 Hz, 1H; CH), 3.92

(s, 3H; OCH₃), 3.60 (s, 3H; CO₂CH₃),

3.36 (dd, J=13.5, 4.9 Hz, 1H; CH₂),

2.93–2.56 (m, 3H; CH₂), 1.66 (m, 1H;

Entry

E. faecium

E. faecalis

Staph.

Sensitive^[b]

Resistant^[c]

Sensitive^[d]

Resistant^[e]

aureus^[f]

1

2

3

2Aj

2Ba

2Bb

>128

>1024

>128

128

>128

>1024

>128

128

>128

>1024

>128

>1024

>128

>1024

>128

128

64

16

64

16

32

8

32

4

8

4

2Bc

5

2Bd

128

64

6

2Be

64

32

8

7

2Bf

16

8

16

32

8

9

2Cb

2Cc

1024

256

1024

32

2

>1024

>256

128

>128

>1024

64

10

11

12

13

14

15

16

17

18

19

20

21

22

20

21

22

23

24

25

26

2Cd

2Ce

2 Da

2Dc

2Dd

2De

2Df

2Dg

2Dh

2Di

2Dj

2Dk

2Dl

2Dm

2Dn

256

32

8

CH

1.44 (s, 9H;

6.6 Hz, 3H; CH₃), 0.94 ppm (d, J=

6.6 Hz, 3H; CH₃);

¹³C NMR

ACHTREUNG

>128

>1024

128

256

128

>128

>1024

128

>128

1024

128

>128

>1024

8

>128

512

4

8

128

>128

512

4

8

128

CACHTREUNG

16

128

(75.0 MHz, CD₃OD): d=175.6, 174.0,

173.3, 171.0, 158.1, 154.1, 152.4, 149.2,

144.1, 137.7, 137.2, 135.6, 135.1, 130.1,

129.4, 127.8, 127.2, 126.4, 109.4, 106.1,

81.0, 74.3, 61.5, 58.2, 56.8, 55.7, 54.2,

52.8, 41.0, 40.7, 37.2, 28.7, 25.7, 23.5,

22.0 ppm; IR (CHCl₃): n˜ =3692, 3651,

3525, 3406, 3032, 3008, 2960, 2937,

2873, 1737, 1687, 1596, 1578, 1536,

1498, 1456, 1438, 1394, 1369, 1352,

>128

64

>1024

>128

16

>1024

8

>1024

>128

128

>1024

64

4

8

64

8

64

4

2

8

64

8

128

>128

1024

32

>1024

>256

1271, 1249, 1192, 1168, 1090 cm^À1

;

2Do

8

2

0.5

4

8

1

8

>128

64

16

1

2

HRMS (ESI): m/z: calcd for

vancomycin

teicoplanin

synercid

daptomycin

>128

4

C₄₀H₄₉N₅O₁₃Na: 830.3225 [M+Na]⁺;

0.125

4

found: 830.3233. For compound 3A’:

8

m.p. 139–1438C; [a]_D=+25.3 (c=0.15

32

16

in MeOH); ¹H NMR (200 MHz,

CDCl₃): d=7.87 (s, 1H; ArH), 7.73 (d,

J=7.6 Hz, 1H; ArH), 7.36–7.30 (m,

2H; ArH, NH), 7.30–6.90 (m, 5H;

[a] MICs=minimum inhibitory concentrations. [b] Bacterial strain L568 (isogenic of L569). [c] Bacterial strain

L2215 clin. isolate Van-A. [d] Bacterial strain L559 (isogenic of L560). [e] Bacterial strain L560. [f] Bacterial

strain L613 clin. isolate Met-R.

ArH), 6.99 (d, J=7.1 Hz, 1H; NH),

6.83 (s, 1H; ArOH), 6.57 (d, J=

8.3 Hz, 1H; NH), 6.47 (s, 1H; ArH),

and the resulting residue was dissolved in dioxane/H₂O (2:1, 450 mL),

neutralized with Na₂CO₃to pH 7, and then more Na₂CO₃(2.06 g,

19.5 mmol) and Boc₂O (1.60 g, 7.11 mmol) were added. After the mixture

had been stirred at room temperature overnight, the mixture was diluted

with H₂O, acidified with 5% HCl to pH 3–4, and then extracted with

EtOAc. The combined organic layers were washed with H₂O, brine, dried

over Na₂SO₄, and concentrated under vacuum. The residue was purified

by flash-column chromatography to afford 4A (4.35 g, 81%). M.p. 123–

1268C; [a]_D=+2.3 (c=0.31 in MeOH); ¹H NMR (300 MHz, CD₃OD):

d=7.81 (dd, J=7.2, 2.0 Hz, 1H; ArH), 7.22 (m, 1H; ArH), 7.18–7.05 (m,

6H; ArH), 6.33 (s, 2H; ArH), 5.15 (d, J=4.2 Hz, 1H; CH), 4.56–4.46 (m,

2H; CH), 4.43 (d, J=4.2 Hz, 1H; CH), 4.01 (dd, J=9.2, 5.6 Hz, 1H;

CH), 3.75 (s, 3H; OCH₃), 3.68 (s, 3H; CO₂CH₃), 3.20 (dd, J=14.0,

4.2 Hz, 1H; CH₂), 2.95–2.65 (m, 3H; CH₂), 1.65–1.50 (m, 1H; CH-

5.27 (s, 1H; ArH), 5.20–5.05 (m, 2H; NH, OH), 4.89 (m, 1H; CH), 4.82

(m, 1H; CH), 4.66 (m, 1H; CH), 4.48 (dd, J=8.9, 2.9 Hz, 1H; CH), 4.15

(m, 1H; CH), 4.04 (s, 3H; OCH₃), 3.73 (s, 3H; CO₂CH₃), 3.50 (dd, J=

13.4, 4.8 Hz, 1H; CH₂), 3.00–2.60 (m, 3H; CH₂), 1.80–1.50 (m, 3H; CH₂,

CHACHTER(UNG CH₃)₂), 1.47 (s, 9H; CACHTREU(NG CH₃)₃), 0.97 (d, J=6.0 Hz, 3H; CH₃),

0.90 ppm (d, J=6.0 Hz, 3H; CH₃); ¹³C NMR (62.5 MHz, CD₃OD): d=

175.8, 174.0, 173.6, 170.8, 158.4, 153.4, 152.7, 151.6, 148.6, 144.2, 137.2,

136.8, 136.1, 134.6, 130.5, 129.4, 128.9, 127.8, 126.8, 109.4, 104.1, 81.0,

74.5, 61.2, 58.4, 56.4, 55.7, 54.4, 52.8, 40.6, 37.2, 27.9, 25.9, 23.4, 21.9 ppm;

IR (CHCl₃): n˜ =3686, 3627, 3525, 3412, 3034, 3011, 2961, 2937, 2874,

1737, 1690, 1598, 1537, 1511, 1456, 1438, 1369, 1352, 1238, 1196, 1169,

1090, 1039 cm^À1; HRMS (ESI): m/z: calcd for C₄₀H₄₉N₅O₁₃Na: 830.3225

[M+Na]⁺; found: 830.3215.

Compound 3B: Following the procedure described for compound 3, com-

pound 3B was prepared by starting from compound 4B. M.p. 132–1368C;

[a]_D=À60.7 (c=1.70 in CHCl₃); ¹H NMR (250 MHz, CD₃OD): d=8.29

(s, 1H; ArH), 7.38 (dd, J=8.5, 2.0 Hz, 1H; ArH), 7.28–7.06 (m, 5H;

ArH), 7.02 (d, J=8.5 Hz, 1H; ArH), 6.32 (d, J=2.0 Hz, 1H; ArH), 5.66

(d, J=2.0 Hz, 1H; ArH), 4.64–4.50 (m, 4H; CH), 4.20 (dd, J=7.9,

7.0 Hz, 1H; CH), 3.91 (s, 3H; OCH₃), 3.74 (s, 3H; CO₂CH₃), 3.42 (dd,

J=14.1, 5.3 Hz, 1H; CH₂), 3.02–2.75 (m, 3H; CH₂), 1.68 (m, 1H; CH),

ACHTREUNG(CH₃)₂), 1.40 (s, 9H; CCAHRTE(UGN CH₃)₃), 1.35–1.25 (m, 2H; CH₂), 0.87 (d, J=

6.0 Hz, 3H; CH₃), 0.85 ppm (d, J=6.0 Hz, 3H; CH₃); ¹³C NMR

(50.3 MHz, CD₃OD): d=176.6, 174.4, 173.4, 173.2, 158.5, 154.6 (d, J=

260 Hz), 152.0, 138.7, 138.1, 137.9, 136.5, 135.9, 135.5, 130.6, 130.4, 129.8,

128.2, 127.9, 119.6 (d, J=21 Hz), 107.8, 81.0, 75.4, 61.1, 57.4, 56.8, 56.1,

54.7, 53.2, 42.0, 38.9, 37.6, 29.0, 26.1, 23.8, 21.9 ppm; IR (CHCl₃): n˜ =

3668, 3460, 3329, 3021, 2958, 1738, 1682, 1606, 1540, 1456, 1353, 1254,

1222, 1166, 1013 cm^À1; HRMS (ESI): m/z: calcd for C₄₀H₅₀N₅O₁₃FNa:

850.3287 [M+Na]⁺; found: 850.3281.

1.55 (m, 2H; CH₂), 1.48 (s, 9H; CCAHTRE(UNG CH₃)₃), 0.97 (d, J=6.5 Hz, 3H; CH₃),

0.92 ppm (d, J=6.5 Hz, 3H; CH₃); ¹³C NMR (62.5 MHz, CD₃OD): d=

173.0, 172.9, 172.1, 166.7, 154.1, 152.5, 151.6, 149.4, 147.9, 144.0, 137.7,

137.3, 137.1, 135.2, 134.3, 130.4, 129.3, 127.7, 126.4, 111.1, 107.6, 80.8,

73.7, 61.4, 59.7, 56.0, 55.8, 54.3, 52.6, 40.9, 40.1, 36.8, 28.5, 25.8, 23.1,

21.9 ppm; IR (CHCl₃): n˜ =3424, 3406, 3029, 3023, 3013, 2959, 2936, 2872,

1741, 1685, 1594, 1534, 1497, 1234, 1230, 1208, 1167, 1038 cm^À1; HRMS

(ESI): m/z: calcd for C₄₀H₄₉N₅O₁₃Na: 830.3225 [M+Na]⁺; found:

830.3215.

Compounds 3Aand 3A ’: A solution of 4A (1.24 g, 1.50 mmol) and anhy-

drous CsF (4.56 g, 30 mmol) in dry DMSO (150 mL) was stirred at room

temperature for 16 h. After this time, the reaction mixture was diluted

with saturated aqueous NH₄Cl, acidified with 5% HCl to pH 4, and ex-

tracted with EtOAc. The combined organic layers were washed with

H₂O, brine, dried over Na₂SO₄, and concentrated under vacuum. The res-

idue was purified by flash-column chromatography to afford 3A and 3A’

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5345

J. Zhu et al.

Compound 18: Pd/C catalyst (10%, 5 mg) was added to a stirred solution

of compound 3A (30 mg, 0.037 mmol) in MeOH (1.0 mL). The mixture

was then hydrogenated under a H₂atmosphere (balloon) at room tem-

perature for 2 h. After this time, the mixture was filtered through a short

celite pad. The solvent was removed and the residue was directly used

for next step. Et₃N (31 mL, 0.223 mmol) and Lauroyl chloride (35 mL,

0.149 mmol) were added to the solution of the above crude product in

CH₂Cl₂(2.0 mL). After the mixture had been stirred at room tempera-

ture for 4 h, the reaction was quenched by the addition of aqueous

NH₄Cl. The two phases were separated and the aqueous phase was ex-

tracted with CH₂Cl₂. The combined organic phases were washed with

brine, dried over Na₂SO₄, and concentrated under vacuum. The mixture

of the above crude product and K₂CO₃(20 mg, 0.145 mmol) in MeOH/

H₂O (10:1, 5.5 mL) was stirred at room temperature for 20 min. The re-

sulting residue was acidified to pH 2–3 with citric acid and concentrated

to remove the volatile. The residue was diluted with water and extracted

with EtOAc. The combined organic layers were washed with H₂O, brine,

dried over Na₂SO₄, and concentrated under vacuum. The residue was pu-

rified by flash-column chromatography (silica gel, heptane/EtOAc 1:2) to

afford 18 (16 mg, 45%). M.p. 78–848C; [a]_D=À17.4 (c=0.81 in CHCl₃);

¹H NMR (250 MHz, CD₃OD): d=7.95 (s, 1H; ArH), 7.25–7.17 (m, 5H;

ArH), 7.07 (dd, J=7.8, 1.9 Hz, 1H; ArH), 6.90 (d, J=7.8 Hz, 1H; ArH),

6.48 (d, J=1.8 Hz, 1H; ArH), 5.40 (d, J=1.8 Hz, 1H; ArH), 5.07 (m,

1H; CH), 4.70–4.42 (m, 3H; CH), 4.30 (m, 1H; CH), 3.96 (s, 3H;

OCH₃), 3.70 (s, 3H; CO₂CH₃), 3.30 (m, 1H; CH₂), 2.91 (dd, J=13.7,

5.0 Hz, 1H; CH₂), 2.82–2.62 (m, 2H; CH₂), 2.19 (t, J=7.2 Hz, 2H; CH₂),

5.48 (d, J=1.6 Hz, 1H; ArH), 5.03 (m, 1H; CH), 4.60 (m, 2H; 2CH),

4.51 (d, J=2.8 Hz, 1H; ArH), 4.19 (dd, J=9.7, 5.5 Hz, 1H; CH), 3.91 (s,

3H; OCH₃), 3.43 (dd, J=13.9, 5.1 Hz, 1H; CH₂), 2.96–2.71 (m, 3H;

CH₂), 1.71–1.49 (m, 3H; CH₂), 1.49 (s, 9H; CACHTRE(UNG CH₃)₃), 1.00 (d, J=6.5 Hz,

3H; CH₃), 0.96 ppm (d, J=6.4 Hz, 3H; CH₃); ¹³C NMR (50.3 MHz,

CD₃OD): d=175.4, 175.2, 172.8, 170.6, 158.0, 153.8, 152.1, 148.9, 143.9,

138.3, 137.0, 136.7, 135.3, 135.2, 129.8, 129.0, 127.3, 126.9, 126.0, 109.0,

105.6, 80.6, 74.2, 68.6, 61.1, 57.5, 57.0, 55.4, 53.8, 40.4, 40.1, 36.9, 28.3,

25.3, 23.1, 21.6 ppm; IR (CHCl₃): n˜ =3668, 3524, 3373, 3024, 2959, 2933,

2872, 1686, 1596, 1536, 1514, 1456, 1438, 1369, 1351, 1272, 1235, 1164,

1117, 1089, 1036 cm^À1

.

Compound 2Ae: To a solution of 3A (30 mg, 0.037 mmol) in MeOH

(1.0 mL) was added SOCl₂(0.1 mL). After the reaction mixture had been

stirred at room temperature for 1 h, it was concentrated to dryness to

afford quantitatively compound 2Ae, which was used without further pu-

rification. [a]_D=À14.4 (c=0.25 in MeOH); ¹H NMR (200 MHz,

CD₃OD): d=8.11 (d, J=1.8 Hz, 1H; ArH), 7.47 (dd, J=8.6, 1.8 Hz, 1H;

ArH), 7.20–7.06 (m, 6H; ArH), 6.49 (d, J=1.9 Hz, 1H; ArH), 5.64 (d,

J=1.9 Hz, 1H; ArH), 4.86 (m, 1H; CH), 4.60–4.42 (m, 3H; 3CH), 4.07

(m, 1H; CH), 3.93 (s, 3H; OCH₃), 3.69 (s, 3H; CO₂CH₃), 3.45 (dd, J=

14.1, 5.3 Hz, 1H; CH₂), 3.20–2.80 (m, 3H; CH₂), 1.80–1.60 (m, 3H; CH,

CH₂), 1.05 (d, J=5.5 Hz, 3H; CH₃), 0.98 ppm (d, J=5.4 Hz, 3H; CH₃);

¹³C NMR (75.0 MHz, CD₃COCD₃): d=173.1, 170.8, 168.3, 170.0, 154.5,

151.3, 150.6, 143.8, 138.5, 136.0, 135.9, 130.0, 128.9, 127.2, 109.0, 75.6,

61.6, 61.4, 57.1, 55.8, 55.0, 51.9, 41.4, 41.0, 37.2, 25.6, 23.1, 23.0 ppm; IR

(CHCl₃): n˜ =3691, 3530, 3039, 3024, 2995, 2954, 2852, 1742, 1677, 1601,

1534, 1437, 1348, 1262, 1232, 1226, 1216, 1202, 1103 cm^À1; HRMS (ESI):

m/z: calcd for C₃₅H₄₂N₅O₁₁: 708.2881 [M+H]⁺; found: 708.2876.

1.86–1.50 (m, 5H; CH, CH₂), 1.46 (s, 9H; CACHTREU(NG CH₃)₃), 1.29 (m, 16H; CH₂),

1.04 (d, J=6.5 Hz, 3H; CH₃), 1.02 (d, J=6.5 Hz, 3H; CH₃), 0.89 ppm (d,

J=6.7 Hz, 3H; CH₃); ¹³C NMR (50.3 MHz, CDCl₃): d=173.7, 173.6,

172.7, 170.7, 169.7, 156.1, 151.7, 150.1, 145.8, 136.2, 134.2, 134.0, 129.8,

129.4, 129.2, 128.8, 127.2, 125.0, 123.6, 107.5, 105.4, 81.0, 73.7, 61.6, 55.2,

54.3, 53.6, 52.8, 41.5, 39.1, 37.2, 37.1, 36.0, 32.0, 29.7, 29.6, 29.4, 29.3, 29.2,

28.4, 25.4, 25.1, 23.3, 22.8, 21.6, 14.2 ppm; IR (CHCl₃): n˜ =3530, 3416,

3032, 3013, 2929, 2856, 1739, 1683, 1597, 1509, 1368, 1265, 1167, 1121,

Compound 21: HOBt (11 mg, 0.081 mmol) and EDC (16 mg,

0.081 mmol) were added to a solution of the above crude amine 2Ae and

N-Boc-3-amino-propionic acid (14 mg, 0.070 mmol) in CH₂Cl₂(3.0 mL).

The reaction mixture was stirred at room temperature for 12 h and was

then diluted with CH₂Cl₂(100 mL). The resulting mixture was washed

with 5% aqueous HCl, saturated NaHCO₃, H₂O, brine, dried over

Na₂SO₄, and concentrated under vacuum. The mixture of the above

crude product and K₂CO₃(14 mg, 0.10 mmol) in MeOH/H₂O (10:1,

5.5 mL) was stirred at room temperature for 20 min. The resulting resi-

due was acidified to pH 2–3 with citric acid and concentrated to remove

the volatile. The residue was diluted with water and extracted with

EtOAc. The combined organic layers were washed with H₂O, brine, dried

over Na₂SO₄, and concentrated under vacuum. The residue was purified

by flash-column chromatography (silica gel, CH₂Cl₂/MeOH 10:1) to

afford 21 (19 mg, 60%). [a]_D=À7.1 (c=0.41 in CHCl₃); ¹H NMR

(250 MHz, CDCl₃): d=7.70 (d, J=1.9 Hz, 1H; ArH), 7.51 (dd, J=8.6,

1.9 Hz, 1H; ArH), 7.30–7.16 (m, 5H; ArH), 7.11 (d, J=8.6 Hz, 1H;

ArH), 7.10 (d, J=6.5 Hz, 1H; NH), 7.01 (d, J=10.2 Hz, 1H; NH), 6.62

(d, J=1.9 Hz, 1H; ArH), 6.24 (m, 2H; NH), 5.43 (d, J=9.1 Hz, 1H;

NH), 5.24 (d, J=1.9 Hz, 1H; ArH), 5.07 (m, 1H; CH), 4.95–4.75 (m,

3H; 3CH), 4.10 (m, 1H; CH), 4.04 (s, 3H; OCH₃), 3.75 (s, 3H;

CO₂CH₃), 3.69 (dd, J=13.7, 3.8 Hz, 1H; CH₂), 3.30 (m, 2H; CH₂), 2.99

(dd, J=13.7, 5.3 Hz, 1H; CH₂), 2.76 (m, 2H), 2.32 (t, J=5.6 Hz, 2H;

1038 cm^À1

; HRMS (ESI): m/z: calcd for C₅₂H₇₃N₅O₁₂Na: 982.5153

[M+Na]⁺; found: 982.5149.

Compound 2Ab: The reaction conditions for preparing compound 19

were similar to those of compound 18, except that the final hydrolysis

with K₂CO₃in MeOH/H₂O was conducted for 20 h. A solution of the

above crude product was dissolved in CH₃CN (1.0 mL) and conc. HCl

(0.1 mL). After being stirred at room temperature for 2 h, the reaction

mixture was concentrated to dryness and the crude product obtained was

purified by HPLC to afford compound 2Ab (15 mg, 85%). M.p. 165–

1688C; [a]_D=À82.4 (c=0.81 in acetone); ¹H NMR (300 MHz, CD₃OD):

d=7.94 (s, 1H; ArH), 7.24–7.06 (m, 7H; ArH), 6.51 (d, J=1.9 Hz, 1H;

ArH), 5.57 (d, J=1.9 Hz, 1H; ArH), 5.11 (d, J=3.1 Hz, 1H; CH), 4.65–

4.55 (m, 2H; CH), 4.38 (d, J=3.1 Hz, 1H; CH), 4.33 (m, 1H, CH), 3.95

(s, 3H; OCH₃), 3.23 (dd, J=13.7, 5.2 Hz, 1H; CH₂), 3.05–2.70 (m, 3H;

CH₂), 2.36 (t, J=7.6 Hz, 2H; CH₂), 1.85–1.55 (m, 5H; CH, CH₂), 1.26

(m, 16H; CH₂), 1.07 (d, J=5.4 Hz, 3H; CH₃), 1.05 (d, J=5.3 Hz, 3H;

CH₃), 0.88 ppm (d, J=6.8 Hz, 3H; CH₃); ¹³C NMR (50.3 MHz, CD₃OD):

d=176.2, 172.5, 170.5, 168.9, 167.4, 153.6, 151.0, 137.4, 135.8, 134.3, 133.2,

130.6, 129.8, 129.3, 129.2, 127.5, 125.0, 123.7, 110.0, 105.7, 74.1, 66.8, 63.0,

61.3, 58.6, 56.9, 54.6, 43.0, 43.0, 39.4, 37.3, 32.7, 28.8, 26.3, 26.3, 25.5, 23.4,

23.2, 22.7, 14.4 ppm; IR (CHCl₃): n˜ =3674, 3529, 3285, 3035, 3009, 2976,

2929, 2856, 1677, 1598, 1531, 1455, 1435, 1345, 1262, 1193, 1121,

CH₂), 1.86 (m, 3H; CH, CH₂), 1.46 (s, 9H; CACHTRE(UNG CH₃)₃), 1.04 (d, J=6.5 Hz,

3H; CH₃), 1.01 ppm (d, J=6.5 Hz, 3H; CH₃); IR (CHCl₃): n˜ =3686,

3627, 3332, 3030, 3014, 2977, 1742, 1684, 1534, 1515, 1436, 1349, 1232,

1202, 1088, 1038 cm^À1; HRMS (ESI): m/z: calcd for C₄₃H₅₄N₆O₁₄Na:

901.3596 [M+Na]⁺; found: 901.3608.

1035 cm^À1

; HRMS (ESI): m/z: calcd for C₄₆H₆₃N₅O₁₀Na: 868.4473

[M+Na]⁺; found: 868.4510.

Compound 23: SOCl₂(0.1 mL) was added to a solution of 21 (18 mg,

0.021 mmol) in MeOH (1.0 mL). After the reaction mixture had been

stirred at room temperature for 1 h, it was concentrated to dryness to

afford the amine quantitatively, which was used without further purifica-

tion. Et₃N (5.6 uL, 0.04 mmol), HOBt (7 mg, 0.049 mmol), and EDC

(10 mg, 0.049 mmol) were added to a solution of the above crude amine

and acid 20 (36 mg, 0.045 mmol) in CH₂Cl₂(3.0 mL). The reaction mix-

ture was stirred at room temperature for 12 h and was then diluted with

CH₂Cl₂(100 mL). The resulting mixture was washed with 5% aqueous

HCl, saturated NaHCO₃, H₂O, brine, dried over Na₂SO₄, and concentrat-

ed under vacuum. The mixture of the above crude product and K₂CO₃

(18 mg, 0.13 mmol) in MeOH/H₂O (10:1, 5.5 mL) was stirred at room

Compound 20: To a solution of 3A (50 mg, 0.062 mmol) in MeOH/H₂O

(10:1, 0.8 mL) was added K₂CO₃(51 mg, 0.372 mmol). After the reaction

mixture had been stirred at room temperature for 24 h, it was concentrat-

ed to remove the volatile. The resulting residue was diluted with H₂O

and washed with heptane/ether (1:1). The aqueous phase was acidified to

pH 2–3 with citric acid and extracted with EtOAc. The organic layer was

washed with H₂O, brine, dried over Na₂SO₄, and concentrated under

vacuum to afford 20 (47 mg, 96%), which was used without further puri-

1

fication. [a]_D=À31.0 (c=0.20 in acetone); H NMR (300 MHz, CD₃OD):

d=8.34 (s, 1H; ArH), 7.38 (dd, J=8.4, 1.9 Hz, 1H; ArH), 7.29–7.11 (m,

5H; ArH), 7.08 (d, J=8.4 Hz, 1H; ArH), 6.56 (d, J=1.6 Hz, 1H; ArH),

5346

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

temperature for 20 min. The resulting residue was acidified to pH 2–3

with citric acid and concentrated to remove the volatile. The residue was

diluted with water and extracted with EtOAc. The combined organic

layers were washed with H₂O, brine, dried over Na₂SO₄, and concentrat-

ed under vacuum. The residue was purified by flash-column chromatog-

raphy (silica gel, CH₂Cl₂/MeOH 10:1) to afford 23 (13 mg, 41%). [a]_D=

À28.3 (c=0.63 in MeOH); ¹H NMR (300 MHz, CD₃CD): d=8.32 (s,

1H), 8.19 (d, J=1.9 Hz, 1H; ArH), 7.43 (dd, J=8.1, 1.4 Hz, 1H; ArH),

7.37 (dd, J=8.4, 1.9 Hz, 1H; ArH), 7.23–7.00 (m, 12H; ArH), 6.60 (d,

J=1.8 Hz, 1H; ArH), 6.51 (d, J=1.9 Hz, 1H; ArH), 5.48 (d, J=1.9 Hz,

1H; ArH), 5.38 (d, J=1.8 Hz, 1H; ArH), 5.02 (d, J=2.4 Hz, 1H; CH),

4.93 (d, J=3.4 Hz, 1H; CH), 4.62–4.52 (m, 5H; 5CH), 4.37 (d, J=

2.4 Hz, 1H; CH), 4.25 (dd, J=9.7, 5.4 Hz, 1H; CH), 4.18 (dd, J=9.8,

5.4 Hz, 1H; CH), 3.91 (s, 3H; OCH₃), 3.92 (s, 3H; OCH₃), 3.67 (s, 3H;

CO₂CH₃), 3.50–3.34 (m, 10H; CH₂), 2.43 (t, J=7.0 Hz, 2H; CH₂), 1.80–

CH), 4.67 (d, J=3.8 Hz, 1H; CH), 4.60 (m, 2H; CH), 4.35–4.10 (m, 4H;

CH, CH, CH₂), 4.04 (m, 1H; CH), 3.85 (s, 3H; OCH₃), 3.71 (s, 3H;

CO₂CH₃), 3.24 (dd, J=13.7, 5.0 Hz, 1H; CH₂), 3.00–2.58 (m, 3H; CH₂),

2.17 (t, J=7.8 Hz, 2H; CH₂), 2.07 (s, 3H; COCH₃), 2.02 (s, 3H;

COCH₃), 2.00 (s, 3H; COCH₃), 1.80–1.45 (m, 5H), 1.48 (s, 9H; CACHTREUNG(CH₃)₃),

1.27 (m, 16H; CH₂), 1.00 (d, J=6.5 Hz, 3H; CH₃), 0.95 (d, J=6.4 Hz,

3H; CH₃), 0.88 ppm (t, J=4.4 Hz, 3H; CH₃); IR (CHCl₃): n˜ =3658, 3432,

3028, 2929, 1744, 1686, 1593, 1536, 1499, 1438, 1369, 1237, 1218, 1159,

1047 cm^À1

; HRMS (ESI): m/z: calcd for C₆₄H₈₈N₆O₂₁Na: 1299.5900

[M+Na]⁺; found: 1299.5911.

Compound 30: LiOH·H₂O (7 mg, 0.16 mmol) was added to a solution of

compound 29 (20 mg, 0.016 mmol) in THF/H₂O (3:1, 4 mL) at 08C. After

the reaction mixture had been stirred for 4 h at 08C, it was acidified with

citric acid to pH 3–4 and extracted with EtOAc. The combined organic

phases were washed with brine, dried over Na₂SO₄, and concentrated

under vacuum to afford compound acid 30 (11 mg, 62%), which proved

to be of sufficient purity for direct use in the next step. M.p. 164–1688C;

[a]_D=+4.2 (c=0.53 in MeOH); ¹H NMR (200 MHz, CD₃OD): d=8.34

(s, 1H; ArH), 7.39 (dd, J=8.5, 1.8 Hz, 1H; ArH), 7.28–7.12 (m, 6H;

ArH), 6.96 (d, J=1.5 Hz, 1H; ArH), 5.71 (d, J=1.5 Hz, 1H; ArH), 5.07

(d, J=8.4 Hz, 1H; CH), 5.05 (m, 1H; CH), 4.60 (m, 3H; CH), 4.18 (dd,

J=8.9, 5.9 Hz, 1H; CH), 3.85 (s, 3H; OCH₃), 4.06–3.90, 3.78–3.40 (m,

7H), 3.00–2.70 (m, 3H; CH₂), 2.25 (t, J=8.3 Hz, 2H; CH₂), 1.80–1.54 (m,

1.50 (m, 6H; CH, CH₂), 1.48 (s, 9H; CCAHTRE(UNG CH₃)₃), 0.98 (d, J=5.1 Hz, 3H;

CH₃), 0.96 (d, J=5.9 Hz, 3H; CH₃), 0.91 ppm (d, J=6.3 Hz, 6H; CH₃);

¹³C NMR (50.3 MHz, CD₃OD): d=175.8, 175.2, 174.7, 174.1, 174.0, 173.4,

173.1, 171.2, 171.1, 158.4, 154.3, 152.7, 152.5, 149.6, 149.4, 114.4, 137.9,

137.5, 135.9, 135.7, 135.4, 130.3, 129.6, 129.5, 128.0, 127.8, 127.4, 126.7,

126.4, 110.0, 109.6, 106.1, 106.0, 81.0, 75.1, 74.5, 61.6, 61.5, 58.3, 57.7, 57.2,

56.0, 55.7, 54.4, 52.9, 50.6, 41.0, 40.6, 40.5, 37.3, 36.9, 36.7, 36.2, 28.7, 25.9,

25.8, 23.6, 23.5, 22.1, 21.9 ppm; IR (CHCl₃): n˜ =3713, 3671, 3524, 3335,

3021, 2991, 2930, 2853, 1736, 1685, 1597, 1534, 1498, 1458, 1350, 1217,

5H), 1.49 (s, 9H; CACHTREU(GN CH₃)₃), 1.27 (m, 16H; CH₂), 1.00 (d, J=6.4 Hz, 3H;

1142 cm^À1

; HRMS (ESI): m/z: calcd for C₇₇H₉₁N₁₁O₂₄Na: 1576.6136

CH₃), 0.95 (d, J=6.3 Hz, 3H; CH₃), 0.86 ppm (t, J=4.4 Hz, 3H; CH₃);

¹³C NMR (50.3 MHz, CD₃OD): d=176.9, 175.9, 175.6, 173.6, 171.1, 158.6,

154.4, 153.3, 149.1, 144.4, 137.9, 137.5, 136.1, 135.5, 130.5, 129.6, 128.7,

127.9, 127.3, 127.1, 126.8, 126.2, 110.9, 109.2, 101.2, 81.2, 78.5, 76.1, 74.6,

72.2, 62.7, 62.0, 58.6, 57.3, 54.8, 54.4, 44.0, 41.0, 40.7, 40.5, 38.1, 37.7, 37.5,

35.0, 33.1, 31.0, 30.6, 30.6, 30.6, 30.4, 29.9, 29.8, 28.8, 27.0, 26.2, 25.9, 23.8,

23.6, 22.2, 14.5 ppm; IR (CHCl₃): n˜ =3648, 3317, 3018, 2991, 2956, 2929,

2856, 1712, 1651, 1598, 1558, 1536, 1513, 1497, 1456, 1435, 1368, 1352,

1283, 1239, 1160, 1105, 1009 cm^À1; MS (ESI): m/z: 1135 [MÀH]⁺.

Compound 2Aj: Following the procedure described for compound 2Ab,

compound 2Aj (8 mg, 57%) was prepared by starting from compound 30

(15 mg, 0.013 mmol). M.p. 2208C; [a]_D=À100 (c=0.25 in acetone);

¹H NMR (200 MHz, CD₃OD): d=8.13 (d, J=1.8 Hz, 1H; ArH), 7.45

(dd, J=8.4, 1.8 Hz, 1H; ArH), 7.30–7.15 (m, 5H; ArH), 7.12 (d, J=8.4,

1H; ArH), 6.91 (s, 1H; ArH), 5.72 (s, 1H; ArH), 5.05 (d, J=8.5 Hz, 1H;

CH), 4.94 (m, 1H; CH), 4.60–4.40 (m, 3H; CH), 4.18 (dd, J=8.9, 5.9 Hz,

1H; CH), 3.85 (s, 3H; OCH₃), 4.06–3.90, 3.78–3.40 (m, 6H), 3.69 (dd, J=

11.8, 5.7 Hz, 1H; CH), 3.25–3.00 (m, 3H; CH₂), 2.89 (t, J=6.2 Hz, 2H;

CH₂), 1.90–1.50 (m, 5H), 1.26 (m, 16H; CH₂), 1.03 (d, J=5.3 Hz, 3H;

CH₃), 0.95 (d, J=5.8 Hz, 3H; CH₃), 0.86 ppm (t, J=5.7 Hz, 3H; CH₃);

IR (CHCl₃): n˜ =3692, 3519, 3028, 3006, 2984, 2934, 2855, 1731, 1706,

1673, 1464, 1395, 1376, 1327, 1250, 1176, 1146, 1046 cm^À1; HRMS (ESI):

m/z: calcd for C₅₂H₇₂N₆O₁₆Na: 1059.4903 [M+Na]⁺; found: 1059.4883.

[M+Na]⁺; found: 1576.6108.

Compound 2Al: LiOH·H₂O (2.2 mg, 0.05 mmol) was added to a solution

of 23 (16 mg, 0.010 mmol) in THF/H₂O (3:1, 2 mL) at room temperature.

After the reaction mixture had been stirred for 4 h, it was acidified with

citric acid to pH 3–4 and extracted with EtOAc. The combined organic

phases were washed with brine, dried over Na₂SO₄, and concentrated

under vacuum to dryness. To a solution of the above crude product was

dissolved in CH₃CN (1.0 mL) and conc. HCl (0.1 mL), and the resulting

mixture stirred at room temperature for 2 h. After this time, the reaction

mixture was concentrated to dryness and the crude product obtained was

purified by HPLC to afford compound 2Al (12 mg, 79%). M.p. >2208C;

[a]_D=À62.4 (c=0.58 in acetone); ¹H NMR (250 MHz, CD₃CD): d=8.23

(s, 1H; ArH), 8.02 (s, 1H; ArH), 7.44 (d, J=6.0 Hz, 1H; ArH), 7.35 (dd,

J=8.0 Hz, 1H; ArH), 7.26–7.00 (m, 12H; ArH), 6.59 (s, 1H; ArH), 6.55

(d, J=1.9 Hz, 1H; ArH), 5.49 (s, 1H; ArH), 5.47 (d, J=1.9 Hz, 1H;

ArH), 5.19 (m, 1H; CH), 5.02 (m, 1H; CH), 4.68–4.52 (m, 4H; 4CH),

4.50 (d, J=2.7 Hz, 1H; CH), 4.32 (d, J=1.7 Hz, 1H; CH), 4.26 (m, 1H;

CH), 4.16 (m, 1H; CH), 3.93 (s, 3H; OCH₃), 3.91 (s, 3H; OCH₃), 3.70–

3.32 (m, 4H; CH₂), 3.10–2.70 (m, 6H; CH₂), 2.47 (t, J=7.4 Hz, 2H;

CH₂), 1.96–1.40 (m, 6H; CH, CH₂), 1.06 (d, J=6.5 Hz, 3H; CH₃), 1.01

(d, J=6.7 Hz, 3H; CH₃), 0.98 (d, J=6.3 Hz, 3H; CH₃), 0.92 ppm (d, J=

5.9 Hz, 3H; CH₃); IR (KBr): n˜ =3658, 3548, 3020, 2997, 2854, 1781, 1710,

1463, 1419, 1364, 1223, 1172 cm^À1

; HRMS (ESI): m/z: calcd for

C₇₁H₈₂N₁₁O₂₂: 1440.5635 [M+H]⁺; found: 1440.5635.

Compound 31: 1-Fluoro-4-nitrobenzene (80 mL, 0.76 mmol) and CsF

(303 mg, 1.94 mmol) were added to a solution of compound 3B (104 mg,

0.129 mmol) in DMSO (4.0 mL). After the reaction mixture had been

stirred at room temperature for 2 h, it was extracted with EtOAc. The

combined organic phases were washed with brine, dried over Na₂SO₄,

and concentrated under vacuum. The residue was purified by flash-

column chromatography (silica gel, CH₂Cl₂/MeOH 100:1) to afford com-

pound 31 (120 mg, 100%). M.p. 124–1268C; [a]_D=À41.5 (c=0.68 in

CHCl₃); ¹H NMR (300 MHz, CDCl₃): d=8.20 (d, J=9.0 Hz, 2H; ArH),

8.18 (s, 1H; ArH), 7.58 (dd, J=8.7, 1.9 Hz, 1H; ArH), 7.34 (m, 1H;

NH), 7.28–7.06 (m, 5H; ArH), 7.05 (d, J=8.7 Hz, 1H; ArH), 6.96 (d, J=

9.0 Hz, 2H; ArH), 6.95 (m, 1H; NH), 6.50 (d, J=9.1 Hz, 1H; NH), 6.42

(d, J=2.3 Hz, 1H; ArH), 5.69 (d, J=2.1 Hz, 1H; ArH), 5.17 (m, 2H;

NH, CH), 4.84 (m, 2H; CH), 4.23 (d, J=2.6 Hz, 1H; CH), 4.10 (m, 1H;

CH), 3.87 (s, 3H; OCH₃), 3.62 (s, 3H; CO₂CH₃), 3.60 (m, 1H; CH₂), 3.08

(dd, J=13.6, 6.4 Hz, 1H; CH₂), 2.94 (dd, J=13.6, 5.3 Hz, 1H; CH₂), 2.84

(dd, J=13.6, 3.4 Hz, 1H; CH₂), 1.62 (m, 3H; CH, CH₂), 1.46 (s, 9H; C-

Compound 29: HBr/AcOH (33%, 400 mL) was added to a solution of

1,3,4,6-tetra-O-acetyl-2-deoxy-2-lauric amido-d-glucopyranose 27 (70 mg,

0.13 mmol) in AcOH (2 mL) at room temperature. After the reaction

mixture had been stirred for 3 h at room temperature, it was diluted with

ice-water and extracted with CH₂Cl₂. The combined organic phases were

washed with cooled aqueous NaHCO₃and brine. The solvent was con-

centrated to about 1 mL under vacuum below30 8C and the resulting sol-

ution was immediately used for the next reaction. Compound 3A (35 mg,

0.043 mmol), 10% aqueous Na₂CO₃(1.0 mL), and catalytic amount of

(nBu)₄NHSO₄were added to the above solution. After the reaction mix-

ture had been stirred at room temperature for 4 h, it was acidified with

citric acid to pH 4–5 and the two phases were separated. The aqueous

phase was extracted with CH₂Cl₂and the combined organic phases were

washed with brine, dried over Na₂SO₄, and concentrated under vacuum.

The residue was purified by flash-column chromatography to afford 29

1

(42 mg, 76%). M.p. 116–1188C; [a]_D=À19.4 (c=1.6 in CHCl₃); H NMR

AHCTRE(UGN CH₃)₃), 0.96 (d, 3H, J=6.4 Hz; CH₃), 0.90 ppm (d, 3H, J=6.4 Hz;

(300 MHz, CD₃OD): d=8.32 (s, 1H; ArH), 7.39 (dd, J=8.6, 2.0 Hz, 1H;

ArH), 7.32–7.14 (m, 5H; ArH), 7.11 (d, J=8.6 Hz, 1H; ArH), 6.82 (d,

J=1.8 Hz, 1H; ArH), 5.79 (d, J=1.8 Hz, 1H; ArH), 5.38 (t, J=9.6 Hz,

1H; CH), 5.32 (d, J=9.0 Hz, 1H; CH), 5.07 (m, 1H; CH), 4.97 (m, 1H;

CH₃); ¹³C NMR (75 MHz, CDCl₃): d=173.3, 171.8, 170.6, 169.0, 163.0,

156.6, 154.3, 148.5, 147.5, 143.2, 142.9, 141.3, 138.2, 135.8, 135.1, 131.6,

129.4 (2C), 128.9 (2C), 127.4, 126.1 (2C), 126.0, 125.7, 116.4 (2C), 114.9,

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5347

J. Zhu et al.

112.6, 81.2, 73.6, 61.8, 55.6, 54.3, 54.1, 53.4, 53.0, 40.1, 38.8, 36.6, 28.4

(3C), 24.8, 23.1, 21.8 ppm; IR (CHCl₃): n˜ =3405, 3026, 2957, 2854, 1693,

1582, 1490, 1432, 1345, 1236, 1165, 1112, 1025, 898, 849 cm^À1; HRMS

(ESI): m/z: calcd for C₄₆H₅₂N₆O₁₅Na: 951.3318 [M+Na]⁺; found:

951.3370.

1491, 1440, 1345, 1232, 1219, 1201, 1165, 1112, 1006, 896, 861 cm^À1

;

HRMS (ESI): m/z: 937 [M+Na]⁺.

Compound 35: Following the procedure described for compound 29, 35

(42 mg, 73%) was prepared by starting from 34 (38 mg, 0.046 mmol).

Compound 35 was purified by preparative TLC (silica gel, CH₂Cl₂/

MeOH 30:1). M.p. 128–1308C; [a]_D=À70.2 (c=0.82 in CHCl₃);

¹H NMR (300 MHz, CDCl₃): d=8.18 (d, J=2.2 Hz, 1H; ArH), 8.18 (d,

J=9.2 Hz, 2H; ArH), 7.59 (dd, J=8.5, 2.2 Hz, 1H; ArH), 7.38 (d, J=

7.7 Hz, 1H; NH), 7.29–7.07 (m, 6H; one NH, ArH), 7.01 (d, J=8.5 Hz,

1H; ArH), 6.97 (d, J=9.2 Hz, 2H; ArH), 6.54 (d, J=9.2 Hz, 1H; NH),

6.33 (d, J=1.8 Hz, 1H; ArH), 5.84 (d, J=9.2 Hz, 1H; NH), 5.76 (d, J=

1.5 Hz, 1H; ArH), 5.23–5.01 (m, 5H; one NH, CH), 4.82 (m, 2H; CH),

4.25 (m, 1H), 4.23 (s, 1H), 4.12 (m, 1H), 4.02 (dd, J=12.5, 3.7 Hz, 1H;

CH₂), 3.79 (m, 1H), 3.69–3.58 (m, 2H), 3.57 (s, 3H), 3.05 (dd, J=13.6,

6.6 Hz, 1H; CH₂), 2.96 (dd, J=13.6, 5.9 Hz, 1H; CH₂), 2.85 (dd, J=14.0,

3.3 Hz, 1H; CH₂), 2.67 (brs, 1H; OH), 1.97 (s, 3H; COCH₃), 1.96 (s, 3H;

COCH₃), 1.94 (s, 3H; COCH₃), 2.00–1.05 (m, 23H), 1.46 (s, 9H; C-

Compound 32 and 33: EtSH (1.5 mL) and AlCl₃(100 mg, 0.72 mmol)

were added to a solution of compound 31 (77 mg, 0.083 mmol) in CH₂Cl₂

(5 mL) at 08C. After the reaction mixture had been stirred at the same

temperature for 2.5 h, the volatile was removed under vacuum and the

residue was diluted with EtOAc and H₂O. The mixture was then stirred

for a further 10 min, after which time, the reaction mixture was extracted

with EtOAc. The combined organic phases were dried over Na₂SO₄and

concentrated under vacuum. The residue was purified by preparative

TLC (silica gel, CH₂Cl₂/MeOH 15:1) to afford compound 32 (9 mg,

13%) and 33 (27 mg, 40%). For compound 32: M.p. >2608C; HRMS

(ESI): m/z: calcd for C₃₉H₄₀N₆O₁₃Na: 823.2506 [M+Na]⁺; found:

823.2514. For compound 33: M.p. 138–1408C; [a]_D=À135 (c=0.54 in

CHCl₃); ¹H NMR (300 MHz, CDCl₃): d=8.18 (d, J=9.2 Hz, 2H; ArH),

7.83 (d, J=1.8 Hz, 1H; ArH), 7.75 (brs, 1H; NH), 7.58 (dd, J=8.5,

1.8 Hz, 1H; ArH), 7.25–7.04 (m, 5H; ArH), 7.01 (d, J=8.5 Hz, 1H;

ArH), 6.96 (d, J=9.2 Hz, 2H; ArH), 6.66 (d, 1H, J=8.1 Hz; NH), 6.45

(d, 1H, J=9.6 Hz; NH), 6.38 (d, J=1.5 Hz, 1H; ArH), 5.55 (s, 1H;

ArH), 5.26 (dd, J=8.8, 1.8 Hz, 1H; CH), 5.00 (s, 1H; CH), 4.88 (m, 1H;

CH), 4.09 (d, J=2.6 Hz, 1H; CH), 3.70 (dd, J=13.6, 5.1 Hz, 1H; CH₂),

3.57 (s, 3H), 3.44 (dd, J=10.3, 4.0 Hz, 1H; CH), 3.36 (brs, 3H; NH₂and

OH), 3.21 (dd, 1H, J=14.0, 4.4 Hz, 1H; CH₂), 2.87–2.77 (m, 2H; CH₂),

1.77 (m, 2H; CH₂), 1.47 (m, 1H; CH), 1.01 (d, J=6.3 Hz, 3H; CH₃),

0.97 ppm (d, J=6.3 Hz, 3H; CH₃); ¹³C NMR (75.0 MHz, CDCl₃): d=

175.4, 171.8, 169.8, 169.4, 162.7, 149.6, 149.2, 143.1, 142.3, 138.6, 138.4,

135.7, 135.2, 129.9 (2C), 128.8 (2C), 127.5, 127.4, 126.8, 126.1 (3C), 125.5,

116.6 (2C), 115.1, 111.9, 73.4, 54.0, 53.9, 53.0, 52.9, 43.7, 38.5, 36.5, 29.8,

25.1, 23.4, 21.5 ppm; IR (CHCl₃): n˜ =3544, 3410, 3024, 2958, 2930, 2854,

1743, 1682, 1607, 1588, 1518, 1490, 1345, 1234, 1199, 1112, 1007, 906,

850 cm^À1; HRMS (ESI): m/z: calcd for C₄₀H₄₃N₆O₁₃: 815.2888 [M+H]⁺;

found: 815.2899.

AHCTRE(GNU CH₃)₃), 0.97 (d, J=5.9 Hz, 3H; CH₃), 0.93 (d, J=5.9 Hz, 3H; CH₃),

0.85 ppm (t, J=7.4 Hz, 3H; CH₃); ¹³C NMR (75.0 MHz, CDCl₃): d=

173.3, 173.2, 171.3, 170.8, 170.7, 170.6, 169.4, 168.7, 162.7, 156.7, 153.7,

148.6, 148.4, 143.2, 143.1, 138.5, 137.8, 135.9, 135.4, 133.5, 129.4 (2C),

128.9 (2C), 127.5, 125.9, 125.8 (2C), 125.5, 117.3 (2C), 115.0, 112.2, 102.3,

81.3, 77.4, 73.7, 72.8, 72.3, 68.1, 61.6, 56.2, 54.3, 54.2, 53.6, 53.0, 40.0, 38.9,

36.9, 36.8, 32.0, 29.7, 29.6, 29.5, 29.4, 29.3, 29.2, 28.4 (3C), 25.6, 24.9, 23.1,

22.8, 21.9, 20.7 (2C), 20.6, 14.2 ppm; IR (CHCl₃): n˜ =3426, 3025, 2929,

2856, 1746, 1685, 1584, 1521, 1492, 1434, 1369, 1345, 1234, 1165, 1112,

1034, 849 cm^À1; HRMS (ESI): m/z: calcd for C₆₉H₈₉N₇O₂₃Na: 1406.5898

[M+Na]⁺; found: 1406.5907.

Compound 2Bd: LiOH·H₂O (24 mg, 0.58 mmol) was added to a solution

of compound 35 (40 mg, 2.9 mmol) in THF/H₂O (3:1, 4.0 mL) at 08C.

After the reaction mixture had been stirred for 2.0 h at 08C, the reaction

mixture was acidified with 5% HCl to pH 3–4 and extracted with

EtOAc. The combined organic phases were washed with brine, dried

over Na₂SO₄, and concentrated under vacuum to afford the correspond-

ing acid, which proved to be of sufficient purity for direct use in the next

step. TFA (0.5 mL) was added to a solution of above acid in CH₂Cl₂

(1.0 mL) at 08C. After the reaction mixture had been stirred at the same

temperature for 1.0 h, it was concentrated to dryness under vacuum. The

residue was purified by preparative TLC (silica gel, CH₂Cl₂/MeOH 6:1)

to afford compound 2Bd (26 mg, 79%). M.p. 175–1778C; ¹H NMR

(300 MHz, CD₃SOCD₃): d=9.08 (d, J=7.4 Hz, 1H; NH), 8.79 (d, J=

6.6 Hz, 1H; NH), 8.29–8.22 (m, 4H; one NH, ArH), 7.56 (d, J=9.2 Hz,

1H; NH), 7.32–7.02 (m, 9H), 6.77 (d, J=1.8 Hz, 1H), 6.58 (d, J=1.8 Hz,

1H), 4.97 (d, J=8.5 Hz, 1H), 4.65 (brs, 6H; OH, NH₂), 4.52 (m, 1H),

4.40 (m, 1H), 4.28 (m, 1H), 3.99 (m, 1H), 3.70 (m, 1H), 3.61 (m, 1H),

3.51 (m, 1H), 3.41 (m, 1H), 3.23 (m, 2H), 3.07 (m, 1H), 2.97 (m, 2H),

2.81 (m, 1H), 2.58 (m, 1H), 1.78–1.00 (m, 23H), 0.88–0.84 ppm (m, 9H);

¹³C NMR (75.0 MHz, CD₃OD): d=173.1, 171.7, 171.1, 169.8, 167.0, 162.8,

154.3, 149.4, 145.8, 142.1, 141.9, 137.6, 137.4, 136.6, 134.0, 129.2 (2C),

127.9 (2C), 126.3, 125.9, 125.7 (2C), 125.1, 124.9, 117.7, 117.1 (2C), 116.2,

102.8, 77.8, 73.5, 71.0, 70.7, 61.2, 57.6, 55.4, 54.7, 53.6, 51.1, 35.6, 34.4,

31.3, 30.4, 29.0 (2C), 28.9, 28.8 (2C), 28.7 (2C), 24.9, 23.9, 22.3, 22.2,

22.1, 13.9 ppm; HRMS (ESI): m/z: calcd for C₃₉H₄₀N₆O₁₃Na: 823.2551

[MÀsugar]⁺; found: 823.2514.

Compound 36: Following the procedure described for compound 29, 36

(24 mg, 76%) was prepared by starting from compound 3B (20 mg,

0.025 mmol). M.p. 102–1058C; [a]_D=À33.8 (c=1.2 in CHCl₃); ¹H NMR

(250 MHz, CD₃OD): d=8.30 (s, 1H; ArH), 7.39 (dd, J=8.5, 2.0 Hz, 1H;

ArH), 7.28–7.07 (m, 5H; ArH), 7.04 (d, J=8.5 Hz, 1H; ArH), 6.63 (d,

J=2.0 Hz, 1H; ArH), 5.93 (d, J=2.0 Hz, 1H; ArH), 5.32 (dd, J=10.1,

10.1 Hz, 1H; CH), 5.15 (d, J=8.5 Hz, 1H; CH), 5.06 (m, 1H; CH), 4.89

(m, 1H; CH), 4.58 (m, 2H; CH), 4.46 (t, J=6.9 Hz, 1H; CH), 4.30–4.10

(m, 4H; CH, CH₂), 3.93 (m, 1H; CH), 3.85 (s, 3H; OCH₃), 3.76 (s, 3H;

CO₂CH₃), 3.41 (dd, J=14.1, 5.5 Hz, 1H; CH₂), 3.04–2.78 (m, 3H; CH₂),

2.17 (t, J=7.5 Hz, 2H; CH₂), 2.03 (s, 3H; COCH₃), 2.03 (s, 3H;

Compound 33: SOCl₂(0.20 mL) was added to a solution of compound 32

(9 mg, 0.011 mmol) in MeOH (1.0 mL). After the reaction mixture had

been stirred at 608C for 12 h, the volatile was removed under vacuum

and the residue was basified with aqueous NaHCO₃to pH 7–8 and ex-

tracted with EtOAc. The combined organic phases were washed with

H₂O and brine, dried over Na₂SO₄, and concentrated under vacuum. The

residue was purified by preparative TLC to afford compound 33 (9 mg,

90%).

Compound 34: NaHCO₃(13 mg, 0.148 mmol) and Boc₂O (9.6 mg,

0.044 mmol) were added to

a solution of compound 33 (30 mg,

0.037 mmol) in dixoane/H₂O (2:1, 2.0 mL). After the reaction mixture

had been stirred at room temperature for 2 d, the reaction mixture was

extracted with EtOAc. The combined organic phases were washed with

H₂O and brine, dried over Na₂SO₄, and concentrated under vacuum. The

residue was purified by preparative TLC (silica gel, CH₂Cl₂/MeOH=30/

1) to afford compound 34 (20 mg, 60%). M.p. 144–1468C; [a]_D=À77.9

(c=0.76 in CHCl₃); ¹H NMR (300 MHz, CDCl₃): d=8.21 (d, J=9.2 Hz,

2H; ArH), 8.11 (s, 1H; ArH), 7.60 (d, J=8.5 Hz, 1H; ArH), 7.28–7.08

(m, 6H; one NH, ArH), 7.03 (d, J=8.5 Hz, 1H; ArH), 6.99 (d, J=

9.2 Hz, 2H; ArH), 6.69 (d, J=8.1 Hz, 1H; NH), 6.42 (d, J=8.8 Hz, 1H;

NH), 6.40 (s, 1H; ArH), 5.64 (s, 1H; ArH), 5.18 (dd, J=8.8, 1.5 Hz, 1H;

CH), 5.01 (d, J=7.4 Hz, 1H; NH), 4.90 (m, 1H; CH), 4.83 (dt, J=9.6,

5.9 Hz, 1H; CH), 4.18 (d, J=2.6 Hz, 1H; CH), 4.11 (m, 1H; CH), 3.64

(dd, J=14.0, 5.5 Hz, 1H; CH₂), 3.58 (s, 3H), 3.12 (dd, J=14.0, 6.6 Hz,

1H; CH₂), 2.94 (dd, J=14.0, 5.5 Hz, 1H; CH₂), 2.83 (dd, J=14.0, 4.0 Hz,

1H; CH₂), 1.61 (m, 3H; CH, CH₂), 1.45 (s, 9H; CACHTER(UNG CH₃)₃), 0.97 (d, J=

6.3 Hz, 3H; CH₃), 0.90 ppm (d, J=6.3 Hz, 3H; CH₃); ¹³C NMR

(75.0 MHz, CDCl₃): d=173.1, 171.7, 170.3, 168.9, 162.5, 156.5, 149.3,

148.6, 143.2, 142.9, 141.9, 138.3, 138.0, 135.7, 135.1, 129.3 (2C), 128.8

(2C), 127.3 (2C), 125.9 (2C), 125.8, 125.5, 116.5 (2C), 114.8, 112.1, 81.0,

73.3, 55.2, 54.3, 54.0, 53.3, 52.9, 39.9, 38.5, 36.5, 28.3 (3C), 24.7, 23.0,

21.6 ppm; IR (CHCl₃): n˜ =3547, 3421, 3023, 2929, 2854, 1689, 1588, 1518,

COCH₃), 2.00 (s, 3H; COCH₃), 1.74–1.50 (m, 5H), 1.48 (s, 9H; CACHTREUNG(CH₃)₃),

1.27 (m, 16H; CH₂), 0.96 (d, J=6.4 Hz, 3H; CH₃), 0.92 (d, J=6.4 Hz,

3H; CH₃), 0.87 ppm (t, J=4.1 Hz, 3H; CH₃); ¹³C NMR (62.5 MHz,

5348

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

CD₃OD): d=176.5, 176.3, 175.4, 173.3, 172.4, 172.2, 171.6, 171.2, 154.4,

151.9, 149.7, 144.2, 138.1, 137.3, 135.8, 134.5, 130.5, 129.4, 127.9, 126.8,

126.5, 112.7, 111.4, 101.0, 81.0, 73.9, 73.6, 73.3, 70.6, 70.0, 63.6, 63.3, 61.9,

60.1, 56.3, 55.8, 55.0, 54.5, 53.0, 41.3, 40.4, 37.4, 37.0, 33.0, 30.7, 30.5, 30.4,

30.3, 30.2, 28.7, 26.8, 25.9, 23.7, 23.2, 22.2, 20.8, 20.7, 20.6, 14.4 ppm; IR

(CHCl₃): n˜ =3658, 3468, 3435, 3020, 2990, 2957, 2929, 2856, 1744, 1676,

1594, 1535, 1508, 1499, 1369, 1237, 1223, 1214, 1258, 1207, 1114, 1088,

rated NaHCO₃, H₂O, brine, dried over Na₂SO₄, and concentrated under

vacuum. The residue was purified by flash-column chromatography to

afford 40 (3.08 g, 93%). M.p. 133–1358C; [a]_D=+18.9 (c=0.55 in

CHCl₃); ¹H NMR (300 MHz, CD₃OD): d=7.82 (dd, J=7.0, 1.8 Hz, 1H;

ArH), 7.34 (m, 1H; ArH), 7.23 (dd, J=11.0, 8.5 Hz, 1H; ArH), 7.30–7.05

(m, 5H; ArH), 6.58 (s, 2H; ArH), 5.28 (d, J=6.3 Hz, 1H; CH), 4.74–4.65

(m, 4H; CH, CH

5.0 Hz, 1H; CH), 3.77 (s, 3H; OCH₃), 3.74 (s, 3H; CO₂CH₃), 3.07–2.85

(m, 4H; CH₂), 1.60–1.40 (m, 3H; CH, CH₂), 1.42 (s, 9H; C(CH₃)₃), 1.34

(d, J=6.0 Hz, 6H; CH(CH₃)₂), 1.33 (d, J=6.0 Hz, 6H; CH(CH₃)₂), 0.88

ACHTRE(UNG CH₃)₂), 4.46 (d, J=6.3 Hz, 1H; CH), 3.94 (dd, J=10.0,

1048 cm^À1

; HRMS (ESI): m/z: calcd for C₆₄H₈₈N₆O₂₁Na: 1299.5900

[M+Na]⁺; found: 1299.5906.

ACHTREUNG

A

ACHTREUNG

Compound 39: LiOH·H₂O (26 mg, 0.63 mmol) was added to a solution of

compound 36 (80 mg, 0.063 mmol) in THF/H₂O (3:1, 4 mL) at 08C. After

the reaction mixture had been stirred for 4 h at 08C, it was acidified with

citric acid to pH 3–4 and extracted with EtOAc. The combined organic

phases were washed with brine, dried over Na₂SO₄, and concentrated

under vacuum to afford compound acid 37 (44 mg, 62%), which proved

to be of sufficient purity for direct use in the next step. HOBt (11 mg,

0.078 mmol) and EDC (15 mg, 0.078 mmol) were added to a solution of

the above crude acid 37 (44 mg, 0.039 mmol) and amine 38 (53 mg,

0.156 mmol) in CH₂Cl₂(2 mL). The reaction mixture was stirred at room

temperature for 12 h, and was then diluted with CH₂Cl₂(100 mL). The

resulting mixture was washed with brine, dried over Na₂SO₄, and concen-

trated under vacuum. The residue was purified by flash-column chroma-

tography to afford 39 (19 mg, 34%). M.p. 165–1688C; [a]_D=+51.4 (c=

0.14 in MeOH); ¹H NMR (300 MHz, CD₃OD): d=8.32 (s, 1H; ArH),

7.47–7.32 (m, 6H; ArH), 7.28–7.19 (m, 3H; ArH), 7.13 (d, J=7.6 Hz,

2H; ArH), 7.03 (d, J=8.9 Hz, 1H; ArH), 6.54 (s, 1H; ArH), 5.79 (d, J=

1.2 Hz, 1H; ArH), 5.39 (s, 1H; CH), 4.96 (d, J=9.1 Hz, 1H; CH), 4.76

(brs, 1H; CH), 4.60–4.58 (m, 2H; CH), 4.23 (t, J=7.5 Hz, 2H; CH), 4.01

(t, J=8.5 Hz, 1H; CH), 3.93 (t, J=13.2 Hz, 2H; CH₂), 3.84 (s, 3H;

OCH₃), 3.76 (dd, J=12.7, 5.1 Hz, 1H; CH₂), 3.63 (dd, J=10.0, 8.4 Hz,

1H; CH₂), 3.54–3.40 (m, 3H; CH, CH, CH₂), 3.28–3.05 (m, 6H; CH,

(d, J=6.7 Hz, 3H; CH₃), 0.85 ppm (d, J=6.7 Hz, 3H; CH₃); ¹³C NMR

(50.3 MHz, CD₃OD): d=175.7, 172.4, 172.2, 170.2, 158.1, 155.5 (d, J=

261 Hz), 152.8, 138.0, 137.9, 137.8, 135.7, 133.4, 130.2, 129.6, 129.4, 127.9,

127.8, 119.2 (d, J=21 Hz), 110.1, 80.7, 72.7, 66.6, 60.9, 56.1, 55.4, 55.1,

54.7, 53.4, 42.0, 38.9, 37.6, 28.8, 25.8, 23.4, 22.6, 22.5, 21.8 ppm; IR

(CHCl₃): n˜ =3627, 3417, 3011, 3024, 2978, 2936, 2115, 1745, 1686, 1623,

1590, 1540, 1498, 1438, 1370, 1351, 1319, 1203, 1159, 1116, 1087 cm^À1

;

HRMS (ESI): m/z: calcd for C₄₆H₆₁N₈O₁₂FNa: 959.4291 [M+Na]⁺;

found: 959.4289.

Compound 41: Following the procedure described for compound 4A,

compound 41 was prepared in 95% yield by starting from compound 40.

M.p. 102–1068C; [a]_D=+8.3 (c=1.48 in CHCl₃); ¹H NMR (300 MHz,

CD₃OD): d=7.80 (dd, J=7.0, 1.8 Hz, 1H; ArH), 7.27 (m, 1H; ArH),

7.24–7.10 (m, 6H; ArH), 6.35 (s, 2H; ArH), 5.16 (d, J=7.0 Hz, 1H; CH),

4.57 (m, 2H; CH), 4.37 (d, J=7.0 Hz, 1H; CH), 3.95 (dd, J=9.5, 5.4 Hz,

1H; CH), 3.77 (s, 3H; OCH₃), 3.73 (s, 3H; CO₂CH₃), 3.15–2.74 (m, 4H;

CH₂), 1.62–1.42 (m, 3H; CH, CH₂), 1.40 (s, 9H; CACHTERU(NG CH₃)₃), 0.87 (d, J=

6.7 Hz, 3H; CH₃), 0.84 ppm (d, J=6.7 Hz, 3H; CH₃); ¹³C NMR

(62.5 MHz, CD₃OD): d=175.7, 172.7, 172.3, 170.2, 158.2, 155.5 (d, J=

260 Hz), 151.7, 138.1, 137.9, 137.7, 136.8, 135.5, 133.8, 130.2, 129.4, 127.8,

127.7, 119.1 (d, J=21 Hz), 108.3, 80.6, 66.0, 60.8, 56.0, 55.1, 54.6, 53.4,

41.9, 38.7, 37.5, 28.9, 28.7, 25.8, 23.4, 21.7 ppm; IR (CHCl₃): n˜ =3652,

3530, 3442, 3020, 2961, 2114, 1736, 1627, 1541, 1508, 1454, 1368, 1353,

CH₂, CH₂, CH₂), 2.37–2.17 (m, 6H; 3CH₂), 2.15 (s, 6H; N

ACHTRE(UNG CH₃)₂),

1.85–1.51 (m, 9H; CH, 4CH₂), 1.49 (s, 9H; C(CH₃)₃), 1.33–1.25 (m,

AHCTREUNG

16H), 0.90 (d, J=6.8 Hz, 3H; CH₃), 0.87 ppm (t, J=6.0 Hz, 6H; CH₃);

¹³C NMR (75.0 MHz, CD₃OD): d=176.9, 176.8, 174.9, 173.8, 173.0, 172.7,

170.8, 170.0, 154.1, 152.5, 152.4, 149.7, 144.4, 139.6, 139.1, 138.0, 137.2,

135.9, 134.0, 130.7, 129.9, 129.6, 129.4, 128.9, 128.8, 128.7, 128.1, 126.9,

126.6, 111.0, 110.9, 101.3, 81.0, 78.4, 75.8, 75.4, 71.9, 62.5, 62.0, 59.2, 58.0,

57.0, 56.8, 55.7, 54.6, 54.5, 45.4, 41.8, 40.6, 39.9, 38.8, 37.7, 33.7, 33.1, 30.9,

30.8, 30.7, 30.6, 30.5, 29.6, 29.1, 28.8, 27.9, 27.0, 26.6, 26.1, 23.8, 23.2, 22.4,

14.5 ppm; IR (CHCl₃): n˜ =3300, 3021, 2929, 2856, 1708, 1660, 1579, 1508,

1438, 1368, 1235, 1162, 1090, 1014 cm^À1; HRMS (ESI): m/z: calcd for

C₇₄H₁₀₇N₁₀O₁₉N: 1439.7714 [M+H]⁺; found: 1439.7737.

1266, 1222, 1209, 1167, 1062 cm^À1

; HRMS (ESI): m/z: calcd for

C₄₀H₄₉N₈O₁₂FNa: 875.3352 [M+Na]⁺; found: 875.3369.

Compound 4D: Ph₃P (1.45 g, 5.5 mmol) and H₂O (100 mL, 5.5 mmol)

were added to a solution of azide 41 (470 mg, 0.55 mmol) in THF

(20 mL) at room temperature. After the reaction mixture had been stir-

red for 36 h at room temperature, the solvent was removed under

vacuum and the residue was purified by flash-column chromatography

(silica gel, CH₂Cl₂/MeOH 35:1) to afford amine 4D (352 mg, 77%). M.p.

136–1398C; [a]_D=À20.8 (c=0.13 in CHCl₃); ¹H NMR (250 MHz,

CD₃OD): d=7.82 (dd, J=6.9, 2.0 Hz, 1H; ArH), 7.35 (m, 1H; ArH),

7.26–7.10 (m, 6H; ArH), 6.27 (s, 2H; ArH), 5.10 (d, J=5.4 Hz, 1H; CH),

4.63 (dd, J=9.9, 4.7 Hz, 1H; CH), 4.50 (dd, J=7.8, 6.2 Hz, 1H; CH),

3.96 (dd, J=10.2, 5.0 Hz, 1H; CH), 3.78 (s, 3H; OCH₃), 3.75 (m, 1H;

CH₂), 3.71 (s, 3H; OCH₃), 3.19 (dd, J=14.0, 4.9 Hz, 1H; CH₂), 3.07 (dd,

J=14.0, 4.9 Hz, 1H; CH₂), 2.95–2.80 (m, 2H; CH₂), 1.63–1.30 (m, 3H;

Compound 2Bf: TFA (0.5 mL) was added to a solution of compound 39

(15 mg, 0.010 mmol) in CH₂Cl₂(1.0 mL). After the reaction mixture had

been stirred at room temperature for 30 min, it was concentrated to dry-

ness under vacuum. The crude product was then purified by HPLC to

afford amine 2Bf (10 mg, 75%). M.p. >2408C; [a]_D=++19.8 (c=0.06 in

MeOH); ¹H NMR (300 MHz, CD₃OD): d=8.48–8.44 (brs, 2H; NH),

8.13 (s, 1H; ArH), 7.48–7.36 (m, 6H; ArH), 7.26–7.10 (m, 5H; ArH),

7.02 (d, J=8.5 Hz, 1H; ArH), 6.54 (d, J=1.7 Hz, 1H; ArH), 5.78 (d, J=

1.2 Hz, 1H; ArH), 5.27 (s, 1H; CH), 5.00 (d, J=8.5 Hz, 1H; CH), 4.90

(d, J=10.2 Hz, 1H; CH), 4.89–4.78 (m, 2H; CH), 4.65 (brs, 1H; CH),

4.50 (t, J=6.2 Hz, 1H; CH), 4.22 (brs, 1H; CH), 4.04–3.88 (m, 3H; CH,

CH₂), 3.85 (s, 3H; OCH₃), 3.75 (dd, J=12.4, 4.6 Hz, 1H; CH₂), 3.65 (dd,

J=10.2, 7.9 Hz, 1H; CH), 3.51–3.39 (m, 3H; 2CH, CH₂), 3.12–2.91 (m,

CH, CH₂), 1.42 (s, 9H; CACTHRE(UGN CH₃)₃), 0.87 (d, J=7.0 Hz, 3H; CH₃), 0.85 ppm

(d, J=7.0 Hz, 3H; CH₃); ¹³C NMR (62.5 MHz, CD₃OD): d=175.4, 172.4,

172.3, 170.3, 157.2, 155.4 (d, J=260 Hz), 151.7, 138.7, 137.8, 137.7, 136.7,

135.5, 133.5, 130.5, 130.2, 129.4, 127.8, 127.7, 119.0 (d, J=21 Hz), 107.4,

80.8, 60.7, 60.3, 58.1, 55.5, 54.9, 54.3, 52.5, 42.0, 38.4, 37.6, 28.7, 25.8, 23.3,

21.8 ppm; IR (CHCl₃): n˜ =3628, 3526, 3435, 3342, 3026, 2961, 2932, 2873,

1750, 1694, 1670, 1539, 1498, 1457, 1368, 1357, 1252, 1221, 1208, 1164,

1048 cm^À1

; HRMS (ESI): m/z: calcd for C₄₀H₅₁N₆O₁₂FNa: 849.4291

6H), 2.78 (brs, 8H; CH₂, N

A

[M+Na]⁺; found: 849.4289.

J=7.6 Hz, 2H; CH₂), 1.96–1.80 (m, 3H; CH, CH₂), 1.78–1.54 (m, 6H; 2

CH₂), 1.38–1.21 (m, 16H), 0.98 (d, J=5.3 Hz, 3H; CH₃), 0.87 (t, J=

6.5 Hz, 3H; CH₃), 0.85 ppm (d, J=5.3 Hz, 3H; CH₃); IR (CHCl₃): n˜ =

3300, 3028, 3021, 3018, 2928, 2855, 1659, 1596, 1533, 1467, 1439, 1351,

Compound 3D: Following the procedure described for compound 3 A,

compound 3D was prepared in 85% yield by starting from compound

4D. M.p. 131–1348C; [a]_D=À66.4 (c=0.22 in CHCl₃); ¹H NMR

(300 MHz, CD₃OD): d=8.33 (s, 1H; ArH), 7.42 (dd, J=8.5, 2.0 Hz, 1H;

ArH), 7.30–7.12 (m, 5H; ArH), 7.07 (d, J=8.5 Hz, 1H; ArH), 6.19 (d,

J=1.9 Hz, 1H; ArH), 5.76 (s, 1H; ArH), 5.11 (s, 1H; CH), 4.67–4.60 (m,

2H; CH), 4.25 (t, J=7.0 Hz, 1H; CH), 4.07 (s, 1H; CH), 3.96 (s, 6H;

OCH₃, CO₂CH₃), 3.42 (dd, J=14.0, 5.5 Hz, 1H; CH₂), 3.06–2.89 (m, 3H;

1237, 1222, 1214, 1204, 1087 cm^À1

; HRMS (ESI): m/z: calcd for

C₆₉H₉₉N₁₀O₁₇: 1339.7190 [M+H]⁺; found: 1339.7202.

Compound 40: HOBt (538 mg, 3.89 mmol) and EDC (834 mg,

4.25 mmol) were added to a solution of amine 7 (1.30 g, 3.54 mmol) and

acid 14 (2.08 g, 3.54 mmol) in CH₂Cl₂(50 mL). The reaction mixture was

stirred at room temperature for 12 h, and was then diluted with CH₂Cl₂

(100 mL). The resulting mixture was washed with 5% aqueous HCl, satu-

CH₂), 1.75 (m, 1H; CH), 1.63 (m, 2H; CH₂), 1.49 (s, 9H; CCAHTRE(UNG CH₃)₃), 1.01

(d, J=6.5 Hz, 3H; CH₃), 0.96 ppm (d, J=6.5 Hz, 3H; CH₃); ¹³C NMR

(75.0 MHz, CD₃OD): d=176.4, 174.3, 173.7, 172.5, 156.7, 154.7, 150.1,

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5349

J. Zhu et al.

145.7, 144.4, 138.5, 137.9, 137.9, 134.0, 130.5, 129.6, 128.0, 127.3, 126.6,

110.9, 107.4, 81.2, 76.7, 61.7, 59.6, 59.0, 56.6, 54.5, 42.9, 41.1, 39.9, 37.5,

28.9, 26.0, 23.5, 22.2 ppm; IR (CHCl₃): n˜ =3628, 3573, 3404, 3028, 3014,

2961, 2935, 2837, 1740, 1684, 1595, 1536, 1497, 1369, 1354, 1234, 1200,

1168, 1116, 1040 cm^À1; HRMS (ESI): m/z: calcd for C₄₀H₅₀N₆O₁₂Na:

829.3384 [M+Na]⁺; found: 829.3395.

Acknowledgements

Financial support from Vicuron Pharmaceuticals (post-doctoral fellow-

ships to Drs. Y. Jia, N. Ma, and Z. Liu), CONACYT, Mexico (Pr. E. Gon-

zalez-Zamora), and CNRS are gratefully acknowledged.

Compound 45: Lauroyl chloride (680 mL, 2.5 mmol) and NaHCO₃

(420 mg, 4.96 mmol) were added to a solution of compound 3D (500 mg,

0.62 mmol) in dioxane/H₂O (2:1, 45 mL). After the reaction mixture had

been stirred at room temperature for 4 h, it was extracted with EtOAc.

The combined organic phases were washed with brine, dried over

Na₂SO₄, and concentrated under vacuum. The residue was purified by

flash-column chromatography to afford compound 45 (540 mg, 74%).

HRMS (ESI): m/z: calcd for C₆₄H₉₄N₆O₁₄Na: 1193.6726 [M+Na]⁺;

found: 1193.6737.

[1] For reviews see: a) D. H. Williams, Nat. Prod. Rep. 1996, 13, 469–

477; b) J. Zhu, Expert Opin. Ther. Pat. 1999, 9, 1005–1019; c) K. C.

Nicolaou, C. N. C. Boddy, S. Bräse, N. Winssinger, Angew. Chem.

1999, 111, 2230–2287; Angew. Chem. Int. Ed. 1999, 38, 2096–2152;

d) R. D. Süssmuth, ChemBioChem 2002, 3, 295–298.

[2] For reviews see: a) C. T. Walsh, S. L. Fisher, I.-S. Park, M. Prahalad,

Z. Wu, Chem. Biol. 1996, 3, 21–28; b) B. K. Hubbard, C. T. Walsh,

Angew. Chem. 2003, 115, 752–789; Angew. Chem. Int. Ed. 2003, 42,

730–765.

[3] D. H. Williams, B. Bardsley, Angew. Chem. 1999, 111, 1264–1286;

Angew. Chem. Int. Ed. 1999, 38, 1172–1193.

[4] R. K. Jain, J. Trias, J. A. Ellman, J. Am. Chem. Soc. 2003, 125, 8740–

8741.

[5] a) C. C. McComas, B. M. Crowley, D. L. Boger, J. Am. Chem. Soc.

2003, 125, 9314–9315; b) J.-G. Lee, C. Sagui, C. Roland, J. Am.

Chem. Soc. 2004, 126, 8384–8385.

[6] Drugs Future 1997, 22, 1049–1050.

[7] M. R. Barbachyn, C. W. Ford, Angew. Chem. 2003, 115, 2056–2070;

Angew. Chem. Int. Ed. 2003, 42, 2010–2023.

Compound 46: The mixture of compound 45 (20 mg, 0.017 mmol) and a

catalytic amount of Pd/C (10%) in MeOH (2.0 mL) was stirred under hy-

drogen at atmospheric pressure at room temperature for 30 min. After

this time, the reaction mixture was filtrated through a pad of Celite and

the filtrate was concentrated to dryness.

A solution of tBuONO

(0.015 mL) in anhydrous degassed DMF (0.5 mL) was then warmed at

758C under argon. A solution of the above amino compound in anhy-

drous degassed DMF (1.0 mL) was added and the resulting mixture was

stirred at 758C for 15 min. After this time, the reaction mixture was

cooled to room temperature and extracted with EtOAc. The combined

organic phases were washed with brine, dried over Na₂SO₄, and concen-

trated under vacuum. The residue was purified by flash-column chroma-

tography to afford compound 46 (10 mg, 52%). M.p. 231–2328C; [a]_D=

À140 (c=0.19 in CHCl₃); ¹H NMR (300 MHz, CDCl₃): d=8.30 (d, J=

8.3 Hz, 1H; NH), 7.62 (d, J=7.7 Hz, 1H; ArH), 7.48 (d, J=10.1 Hz, 1H;

NH), 7.37 (dd, J=8.6, 2.8 Hz, 1H; ArH), 7.21 (t, J=7.6 Hz, 3H; ArH),

7.09 (dd, J=7.6, 1.6 Hz, 2H; ArH), 6.92 (dd, J=8.3, 2.4 Hz, 1H; ArH),

6.89 (dd, J=8.6, 2.4 Hz, 1H; ArH), 6.11 (d, J=8.3 Hz, 1H; NH), 6.10 (d,

J=2.1 Hz, 1H; ArH), 6.09 (d, J=5.5 Hz, 1H; NH), 5.46 (d, J=8.4 Hz,

1H; CH), 5.20–5.12 (m, 1H; CH), 5.03 (m, 2H, ArH; CH), 4.88 (d, J=

8.8 Hz, 1H; NH), 4.24–4.13 (m, 1H; CH), 3.95 (s, 3H; CO₂CH₃), 3.93 (s,

3H; OCH₃), 3.75 (d, J=5.5 Hz, 1H; CH), 3.62 (dd, J=13.4, 4.2 Hz, 1H;

CH₂), 3.31 (dd, J=13.8, 4.8 Hz, 1H; CH₂), 2.85 (dd, J=13.8, 4.8 Hz, 1H;

CH₂), 2.78 (dd, J=13.4, 3.6 Hz, 1H; CH₂), 2.56 (t, J=7.4 Hz, 2H; CH₂),

2.51–2.40 (m, 1H; CH₂), 2.32–2.18 (m, 1H; CH₂), 1.81–1.71 (m, 2H),

[8] F. P. Tally, M. F. Debruin, J. Antimicrob. Chemother. 2000, 46, 523–

526.

[9] A. Malabarba, T. I. Nicas, R. C. Thompson, Med. Res. Rev. 1997, 17,

69–137.

[10] R. Nagarajan, A. A. Schabel, J. L. Occolowitz, F. T. Counter, J. L.

Ott, A. M. Felty-Duckworth, J. Antibiot. 1989, 42, 63–72.

[11] D. JabØs, C. Candiani, G. Romanó, C. Brunati, M. Riva, M. Cavaleri,

Antimicrob. Agents Chemother. 2004, 48, 1118–1123.

[12] D. Kahne, C. Leimkuhler, W. Lu, C. T. Walsh, Chem. Rev. 2005, 105,

425–448.

[13] a) G. J. Sharman, A. C. Try, R. J. Dancer, Y. R. Cho, T. Staroske, B.

Bardsley, A. J. Maguire, M. A. Cooper, D. P. OꢀBrien, D. H. Willi-

mans, J. Am. Chem. Soc. 1997, 119, 12041–12047; b) D. H. Williams,

A. J. Maguire, W. Tsuzuki, M. S. Westwell, Science 1998, 280, 711–

714.

[14] a) M. Ge, Z. Chen, H. R. Onishi, J. Kohler, L. L. Silver, R. Kerns, S.

Fukuzawa, C. Thompson, D. Kahne, Science 1999, 284, 507–511;

b) U. S. Eggert, N. Ruiz, B. V. Falcone, A. A. Branstrom, R. C. Gold-

man, T. J. Silhavy, D. Kahne, Science 2001, 294, 361–364.

[15] R. S. Roy, P. Yang, S. Kodali, Y. Xiong, R. M. Kim, P. R. Griffin,

H. R. Onishi, J. Kohler, L. L. Silver, K. Chapman, Chem. Biol. 2001,

8, 1095–1106.

[16] a) L. Chen, D. Walker, B. Sun, Y. Hu, S. Walker, D. Kahne, Proc.

Natl. Acad. Sci. USA 2003, 100, 5658–5663; b) C. Leimkuhler, L.

Chen, D. Barrett, G. Panzone, B. Sun, B. Falcone, M. Oberthür, S.

Donadio, S. Walker, D. Kahne, J. Am. Chem. Soc. 2005, 127, 3250–

3251.

[17] M. Bois-Choussy, L. Neuville, R. Beugelmans, J. Zhu, J. Org. Chem.

1996, 61, 9309–9322.

[18] a) R. Xu, G. Greiveldinger, L. E. Marenus, A. Cooper, J. A. Ellman,

J. Am. Chem. Soc. 1999, 121, 4898–4899; b) K. A. Ahrendt, J. A.

Olsen, M. Wakao, J. Trias, J. A. Ellman, Bioorg. Med. Chem. Lett.

2003, 13, 1683–1686.

1.69–1.58 (m, 2H), 1.50–1.40 (m, 3H), 1.45 (s, 9H; CACHTREU(GN CH₃)₃), 1.31–1.22

(m, 32H), 0.93 (d, J=6.3 Hz, 3H; CH₃), 0.89 (t, J=6.7 Hz, 3H; CH₃),

0.87 (t, J=6.7 Hz, 3H; CH₃), 0.76 ppm (d, J=6.3 Hz, 3H; CH₃);

¹³C NMR (75.0 MHz, CDCl₃): d=176.2, 174.1, 171.7, 169.2, 168.8, 168.7,

155.8, 155.3, 154.8, 144.4, 140.0, 136.0, 134.3, 134.0, 131.2, 130.5, 129.7,

128.8, 127.3, 123.8, 122.4, 113.1, 111.7, 80.0, 61.0, 59.5, 54.9, 53.8, 53.1,

52.8, 40.6, 38.6, 37.1, 37.0, 34.3, 32.0, 29.8, 29.7, 29.7, 29.6, 29.5, 29.4, 29.3,

29.2, 28.5, 26.5, 25.2, 24.7, 23.3, 22.8, 22.0, 14.2 ppm; IR (CHCl₃): n˜ =

3402, 3314, 3018, 2957, 2929, 2856, 1747, 1708, 1683, 1642, 1587, 1505,

1468, 1439, 1367, 1311, 1222, 1217, 1204, 1163, 1139, 1107, 1031 cm^À1

;

HRMS (ESI): m/z: calcd for C₆₄H₉₅N₅O₁₂Na: 1148.6875 [M+Na]⁺;

found: 1148.6855.

Compound 2Df: Following the procedure described for compound 2Ab,

compound 2Df (4.0 mg, 64%) was prepared by starting from compound

46 (8.6 mg, 7.6 mmmol). [a]_D=+7.8 (c=0.08 in MeOH); ¹H NMR

(300 MHz, CD₃OD): d=7.74 (dd, J=8.4, 1.6 Hz, 1H; ArH), 7.45 (dd, J=

8.3, 2.1 Hz, 1H; ArH), 7.27–7.15 (m, 3H; ArH), 7.13–7.05 (m, 3H; ArH),

6.72 (dd, J=8.4, 2.5 Hz, 1H; ArH), 6.33 (d, J=2.0 Hz, 1H; ArH), 5.27

(d, J=2.0 Hz, 1H; ArH), 5.11 (d, J=8.0 Hz, 1H; CH), 4.73 (dd, J=5.3,

3.8 Hz, 1H; CH), 4.69 (d, J=8.0 Hz, 1H; CH), 4.37 (t, J=6.1 Hz, 1H;

CH), 4.12 (t, J=7.2 Hz, 1H; CH), 3.90 (s, 3H; OCH₃), 3.35 (dd, J=14.1,

5.3 Hz, 1H; CH₂), 2.99 (dd, J=14.1, 4.8 Hz, 1H; CH₂), 2.92 (dd, J=14.1,

3.8 Hz, 1H; CH₂), 2.86 (dd, J=14.1, 6.7 Hz, 1H; CH₂), 2.12 (t, J=7.8 Hz,

2H; CH₂), 1.65–1.57 (m, 3H; CH, CH₂), 1.31–1.20 (m, 18H), 0.99 (d, J=

5.9 Hz, 3H; CH₃), 0.91 (d, J=5.9 Hz, 3H; CH₃), 0.88 ppm (t, J=6.8 Hz,

3H; CH₃); HRMS (ESI): m/z: calcd for C₄₆H₆₃N₅O₉Na: 852.4523

[M+Na]⁺; found: 852.4528.

[19] a) C. J. Arnusch, R. J. Pieters, Eur. J. Org. Chem. 2003, 3131–3138;

for the synthesis of side-chain knotted bicyclic pentapeptide see:

b) H. T. Ten Brink, D. T. S. Rijkers, J. Kemmink, H. W. Hilbers,

R. M. J. Liskamp, Org. Biomol. Chem. 2004, 2, 2658–2663; after the

acceptance

of

this

manuscript,

synthesis

of

[y·CH₂NH]Tpg₄]vancomycin aglycon was reported see: c) B. M.

Crowley, D. L. Boger, J. Am. Chem. Soc. 2006, 128, 2885–2892.

[20] Total synthesis of vancomycin see: a) D. A. Evans, M. R. Wood,

B. W. Trotter, T. I. Richardson, J. C. Barrow, J. L. Katz, Angew.

Chem. 1998, 110, 2864–2868; Angew. Chem. Int. Ed. 1998, 37, 2700–

5350

www.chemeurj.org

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Chem. Eur. J. 2006, 12, 5334 – 5351

Design and Synthesis of Simple Macrocycles

FULL PAPER

2704; b) K. C. Nicolaou, M. Takayanagi, N. F. Jain, S. Natarajan,

A. E. Koumbis, T. Bando, J. M. Ramanjulu, Angew. Chem. 1998,

110, 2881–2883; Angew. Chem. Int. Ed. 1998, 37, 2717–2719;

c) D. L. Boger, S. Miyazaki, S. H. Kim, J. H. Wu, O. Loiseleur, S. L.

Castle, J. Am. Chem. Soc. 1999, 121, 3226–3227; total synthesis of

teicoplanin see: d) D. L. Boger, S. H. Kim, S. Miyazaki, H. Strittmat-

ter, J.-H. Weng, Y. Mori, O. Rogel, S. L. Castle, J. J. McAtee, J. Am.

Chem. Soc. 2000, 122, 7416–7417; e) D. A. Evans, J. L. Katz, G. S.

Peterson, T. Hintermann, J. Am. Chem. Soc. 2001, 123, 12411–

12413; total synthesis of ristocetin aglycon see: B. M. Crowley, Y.

Mori, C. C. McComas, D. Tang, D. L. Boger, J. Am. Chem. Soc.

2004, 126, 4310–4317.

[27] Z. Liu, N. Ma, Y. Jia, M. Bois-Choussy, A. Malabarba, J. Zhu, J.

Org. Chem. 2005, 70, 2847–2850.

[28] For the definition of planar chirality see: E. L. Eliel, S. H. Wilen,

Stereochemistry of Organic Compounds, Wiley, NewYork, 1994,

Chapter 14.

[29] For temperature-controlled atropdiastereoselective cycloetherifica-

tion see: R. Beugelmans, M. Bois-Choussy, C. Vergne, J.-P. Bouillon,

J. Zhu, Chem. Commun. 1996, 1029–1030.

[30] For designed substrate-controlled atropdiastereoselective cycloether-

ification see: K. C. Nicolaou, C. N. C. Boddy, J. Am. Chem. Soc.

2002, 124, 10451–10455.

[31] G. Islas-Gonzalez, M. Bois-Choussy, J. Zhu, Org. Biomol. Chem.

2003, 1, 30–32.

[32] For X-ray structure see: P. J. Loll, A. E. Bevivino, B. D. Korty, P. H.

Axelsen, J. Am. Chem. Soc. 1997, 119, 1516–1522.

[21] For modification of vancomycin-type glycopeptide antibiotics by re-

programming the biosynthesis pathway see: a) S. Weist, C. Kittel, D.

Bischoff, B. Bister, V. Pfeifer, G. J. Nicholson, W. Wohlleben, R. D.

Süssmuth, J. Am. Chem. Soc. 2004, 126, 5942–5943; b) D. Bischoff,

B. Bister, M. Bertazzo, V. Pfeifer, E. Stegmann, G. J. Nicholson, S.

Keller, S. Pelzer, W. Wohlleben, R. D. Süssmuth, ChemBioChem

2005, 6, 267–272, and references therein.

[22] For selected examples of controlled degradation of glycopeptides

see: a) A. Malabarba, R. Ciabatti, J. Med. Chem. 1994, 37, 2988–

2990; b) A. Malabarba, R. Ciabatti, J. Kettenring, P. Ferrari, K.

VØkey, E. Bellasio, M. Denaro, J. Org. Chem. 1996, 61, 2137–2150;

c) A. Malabarba, R. Ciabatti, M. Maggini, P. Ferrari, L. Colombo,

M. Denaro, J. Org. Chem. 1996, 61, 2151–2157; d) A. Malabarba, R.

Ciabatti, E. Gerli, F. Pipamont, P. Ferrari, L. Colombo, E. N. Olsu-

fyeva, A. Y. Pavlov, M. I. Reznikova, E. I. Lazhko, M. N. Preobraz-

henskaya, J. Antibiot. 1997, 50, 70–81; e) A. Malabarba, T. I. Nicas,

R. Ciabatti, Eur. J. Med. Chem. 1997, 32, 459–478; f) A. Y. Pavlov,

M. N. Preobrazhenskaya, A. Malabarba, R. Ciabatti, L. Colombo, J.

Antibiot. 1998, 51, 73–78; g) G. Panzone, P. Ferrari, M. Kurz, A.

Trani, J. Antibiot. 1998, 51, 872–879; h) S. S. Printsevskaya, A. Y.

Pavlov, E. N. Olsufyeva, E. P. Mirchink, M. N. Preobrazhenskaya, J.

Med. Chem. 2003, 46, 1204–1209, and references therein.

[33] Representative examples: a) U. N. Sundram, J. H. Griffin, T. I.

Nicas, J. Am. Chem. Soc. 1996, 118, 13107–13108; b) J. Rao, G. M.

Whitesides, J. Am. Chem. Soc. 1997, 119, 10286–10290; c) J. Rao, J.

Lahiri, L. Isaacs, R. M. Weis, G. M. Whitesides, Science 1998, 280,

708–711; d) T. Staroske, D. H. Williams, Tetrahedron Lett. 1998, 39,

4917–4920; e) M. Adamczyk, J. A. Moore, S. D. Rege, Z. Yu,

Bioorg. Med. Chem. Lett. 1999, 9, 2437–2440; f) J. H. Griffin, M. S.

Linsell, M. B. Nodwell, Q. Chen, J. L. Pace, K. L. Quast, K. M.

Krause, L. Farrington, T. X. Wu, D. L. Higgins, T. E. Jenkins, B. G.

Christensen, J. K. Judice, J. Am. Chem. Soc. 2003, 125, 6517–6531.

[34] For a reviewon the polyvalent interaction in biological systems see:

M. Mammen, S.-K. Choi, G. M. Whitesides, Angew. Chem. 1998,

110, 2908–2953; Angew. Chem. Int. Ed. 1998, 37, 2754–2794.

[35] P. Boullanger, J. Banoub, G. Descotes, Can. J. Chem. 1987, 65,

1343–1348.

[36] R. R. Schmidt, Angew. Chem. 1986, 98, 213–236; Angew. Chem. Int.

Ed. Engl. 1986, 25, 212–235.

[37] G. Islas-Gonzalez, J. Zhu, J. Org. Chem. 1999, 64, 914–924.

[38] a) Y. Inouye, K. Onodera, S. Kitaoka, H. Ochiai, J. Am. Chem. Soc.

1957, 79, 4218–4222; b) F. Micheel, H. Petersen, Chem. Ber. 1959,

92, 298–304; c) H. M. Flowers, R. W. Jeanloz, J. Org. Chem. 1963,

28, 1564–1567.

[39] Crysatallin 2-deoxy-2-trifluoroacetamido-a-d-glucopyranosyl bro-

mide is an exception. The strong electron-withdrawing effect of the

trifluoro acetyl function renders it more stable see: M. L. Wolfrom,

H. B. Bhat, J. Org. Chem. 1967, 32, 1821–1823.

[40] a) T. Temal-Laꢃb, J. Chastanet, J. Zhu, J. Am. Chem. Soc. 2002, 124,

583–590; b) P. Cristau, T. Temal-Laꢃb, M. Bois-Choussy, M. T.

Martin, J. P. Vors, J. Zhu, Chem. Eur. J. 2005, 11, 2668–2679, and

references therein.

[41] S. D. Dong, M. Oberthür, H. C. Losey, J. W. Anderson, U. S. Eggert,

M. W. Peczuh, C. T. Walsh, D. Kahne, J. Am. Chem. Soc. 2002, 124,

9064–9065.

[23] a) R. Kerns, S. D. Dong, S. Fukuzawa, J. Carbeck, J. Kohler, L.

Silver, D. Kahne, J. Am. Chem. Soc. 2000, 122, 12608–12609; b) Z.

Chen, U. S. Eggert, S. D. Dong, S. J. Shaw, B. Sun, J. V. LaTour, D.

Kahne, Tetrahedron 2002, 58, 6585–6594; c) B. Sun, Z. Chen, U. S.

Eggert, S. J. Shaw, J. V. LaTour, D. Kahne J. Am. Chem. Soc. 2001,

123, 12722–12723.

[24] For reviews see reference [1c] and a) J. Zhu, Synlett 1997, 133–144;

b) J. S. Sawyer, Tetrahedron 2000, 56, 5045–5065.

[25] Part of this work has been published as communications: a) N. Ma,

Y. Jia, Z. Liu, E. Gonzalez-Zamora, M. Bois-Choussy, A. Malabar-

ba, C. Brunati, J. Zhu, Bioorg. Med. Chem. Lett. 2005, 15, 743–746;

b) Y. Jia, E. Gonzalez-Zamora, N. Ma, Z. Liu, M. Bois-Choussy, A.

Malabarba, C. Brunati, J. Zhu, Bioorg. Med. Chem. Lett. 2005, 15,

4594–4599.

[26] C. Vergne, M. Bois-Choussy, J. Ouazzani, R. Beugelmans, J. Zhu,

Tetrahedron: Asymmetry 1997, 8, 391–398.

Received: February 1, 2006

Published online: April 24, 2006

Chem. Eur. J. 2006, 12, 5334 – 5351

ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

www.chemeurj.org

5351

Article Doi

Design and synthesis of simple macrocycles active against Vancomycin-resistant Enterococci (VRE)

DOI: 10.1002/chem.200600137

Source and publish data:

Authors:

Article abstract of DOI:10.1002/chem.200600137

Full text of DOI:10.1002/chem.200600137

Products guided by the article

R&D Labs maybe for 868684-97-3

Relevant to this article

Hot Product