Synthesis and biological activity of novel nonsteroidal progesterone receptor antagonists based on cyclocymopol monomethyl ether

DOI: 10.1021/jm950747d

Source and publish data:

Journal of Medicinal Chemistry p. 1778 - 1789 (1996)

Update date:2022-07-29

Topics:

Authors:

Hamann, Lawrence G.

Farmer, Luc J.

Johnson, Michael G.

Bender, Steven L.

Mais, Dale E.

Wang, Ming-Wei

Crombie, Diane

Goldman, Mark E.

Jones, Todd K.

Read Full Text PDF DownLoad Join now for total 90,000,000 free articles

Article abstract of DOI:10.1021/jm950747d

A novel class of nonsteroidal progesterone receptor antagonists has been synthesized and was shown to exhibit moderate binding affinity for hPR-A, the ability to inhibit the transcriptional activity of human progesterone receptor (hPR) in cell-based assays, and anti-progestational activity in a murine model. Cyclocymopol monomethyl ether, a component of the marine alga Cymopolia barbara was weakly active in random screening against PR. Investigations into the SAR surrounding the core of this natural product lead structure resulted in improved in vitro activity. In contrast to the cross- reactivity profiles observed with known steroidal anti-progestins, compounds of the general structural class described display a high degree of selectivity for the progesterone receptor and no functional activity on the glucocorticoid receptor.

Full text of DOI:10.1021/jm950747d

1778

J . Med. Chem. 1996, 39, 1778-1789

Syn th esis a n d Biologica l Activity of Novel Non ster oid a l P r ogester on e Recep tor

An ta gon ists Ba sed on Cyclocym op ol Mon om eth yl Eth er

Lawrence G. Hamann,*^,†Luc J . Farmer,^†Michael G. J ohnson,^†Steven L. Bender,^†,‡Dale E. Mais,^§

Ming-Wei Wang,^§Diane Crombie,^§Mark E. Goldman, and Todd K. J ones^†

Departments of Endocrine Chemistry Research, Endocrine Research, and New Leads Discovery, Ligand Pharmaceuticals, Inc.,

9393 Towne Centre Drive, San Diego, California 92121

Received October 10, 1995^X

A novel class of nonsteroidal progesterone receptor antagonists has been synthesized and was

shown to exhibit moderate binding affinity for hPR-A, the ability to inhibit the transcriptional

activity of human progesterone receptor (hPR) in cell-based assays, and anti-progestational

activity in a murine model. Cyclocymopol monomethyl ether, a component of the marine alga

Cymopolia barbata was weakly active in random screening against PR. Investigations into

the SAR surrounding the core of this natural product lead structure resulted in improved in

vitro activity. In contrast to the cross-reactivity profiles observed with known steroidal anti-

progestins, compounds of the general structural class described display a high degree of

selectivity for the progesterone receptor and no functional activity on the glucocorticoid receptor.

In tr od u ction

androgen receptor (hAR). The greater selectivity ex-

hibited by these nonsteroidal PR antagonists should

provide therapeutic benefit without steroid-related li-

abilities in any potential chronic clinical use.

As part of a high-throughput screening effort using

the cotransfection assay,⁷we discovered that a crude

organic extract of the marine alga C. barbata exhibited

activity against hPR-B1. The active components were

isolated from the extract and fully characterized as two

diastereomers of cyclocymopol monomethyl ether (1 and

2).⁸These natural products are of mixed biogenetic

origin, containing both a terpenoid aliphatic portion and

a polyketide-derived aromatic portion.

Small molecule antagonists of the progesterone recep-

tor (PR) have important roles in health care, including

potential use as therapeutic agents for treatment of

uterine leiomyomas,^1aendometriosis,^1bbreast cancer,^1c

and meningiomas,^1das well as potential use in fertility

control.^1ePR is a member of the superfamily of intra-

cellular receptors (IRs), including sex steroid receptors,

which act as prototypic ligand-dependent transcription

factors (TFs) to control gene expression, thereby influ-

encing cell growth, differentiation, and other physiologic

processes.²All of the known PR antagonists currently

available or in clinical development are derived from

steroids, and consequently, many have significant cross-

reactivities with other steroid hormone receptors.³As

part of a program designed to identify and develop

compounds of novel structural classes which more

selectively interact with the PR to regulate its various

functions, we have synthesized and observed PR an-

tagonist activity in analogues of cyclocymopol monometh-

yl ether, a marine natural product from the alga

Cymopolia barbata, found in shallow coastal waters

near the Florida Keys.⁴Beginning with this weakly

active natural product as a lead structure, we have

prepared numerous analogues through total synthesis

and semisynthetic efforts which have been shown to

exhibit moderate affinity for human PR-A (hPR-A),

inhibit the transcriptional activity of hPR in cell-based

assays, and display pharmacological efficacy in a stan-

dard murine model.⁵This series of analogues is highly

selective for PR over human glucocorticoid receptor

(hGR), with virtually no functional activity on hGR, and

PR-A/GR affinity ratios ranging from 8- to 237-fold, in

contrast to that observed with the known steroidal anti-

progestins, such as RU486 and ZK98,299.⁶However,

some analogues have moderate affinities for the human

The 3(R) isomer (1) inhibited progesterone-stimulated

reporter gene expression in the cotransfection assay

with an IC₅₀value of 549 ( 55 nM. The 3(S) isomer (2)

exhibited agonist activity 80% of that of progesterone,

with an EC₅₀value of 35 ( 2 nM. None of the other

related compounds isolated from the complex mixture

of secondary metabolites of the alga, notably cymopol

(3),⁹were active in the hPR cotransfection assay. An

effort was initiated to further examine this novel

pharmacophore and to elucidate structure-activity

relationships using several biological assays. These

include the cotransfection assay with hPR-B1, a high-

throughput T-47D (human breast carcinoma cell) alka-

line phosphatase assay, hPR-A receptor binding,⁷and

a murine uterine decidualization assay.¹⁰

^†Department of Endocrine Chemistry Research.

^‡Present address: Agouron Pharmaceuticals Inc., 10350 N. Torrey

Pines Rd., Suite 100, La J olla, CA 92037.

Ch em istr y

^§Department of Endocrine Research.

Previous synthetic efforts toward the cyclocymopols

have successfully utilized a biomimetic approach,¹¹

though a more convergent approach was desired for our

purposes. A modular chemical synthesis of the general

Department of New Leads Discovery.

^|Present address: Signal Pharmaceuticals Inc., 5555 Oberlin Dr.,

San Diego, CA 92121.

^XAbstract published in Advance ACS Abstracts, April 1, 1996.

Novel Nonsterodial Progesterone Receptor Antagonists

J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9 1779

Sch em e 1^a

Sch em e 3^a

(a) TBSCl, imidazole, DMAP, CH₂Cl₂, rt; (b) NaBH₄, MeOH,

0 °C; (c) Ph₃P, Br₂, DMF, 0 °C.

Sch em e 2^a

(a) TMSCH₂Li, THF, -78 °C; (b) TBAF, THF, Ac₂O, 0 °C; (c)

HF/py, THF; (d) Et₂Zn, ClCH₂I, 1,2-DCE.

Sch em e 4^a

(a) MeLi, Et₂O, -78 °C, then 1 N HCl; (b) TMSCH₂Li, THF,

-78 °C; (c) HF/py, THF, rt.

(a) LDA, THF -78 °C; (b) 5, f rt; (c) H₂, 5% Pd on C, EtOAc;

(d) TMSCH₂Li, THF, -78 °C; (e) HF/py, THF; (f) MeMgBr, CuI,

THF, -55 °C; (g) (CH₂dCH)₂MgBr, CuBr‚Me₂S, THF, -50 °C; (h)

O₃, MeOH, -78 °C, then Me₂S; (i) LiTEPA, THF, 0 °C.

thylenation of 7a gave diene 8b. Compounds 8c and

8d were prepared from isophorone and 4,4-dimethylcy-

clopent-2-en-1-one respectively in an analogous fashion,

though preparation of 8d required use of the corre-

sponding organocerium methylenation reagent.¹⁶Con-

jugate addition of methyl cuprate to enone 7a , followed

by Peterson methylenation/desilylation, gave 9. Simi-

larly, conjugate addition of vinyl cuprate¹⁷to enone 7a

allowed installation of varied functionality at this

position. Ozonolysis of the vinyl group gave an aldehyde

which was selectively reduced using lithium tris[(3-

ethyl-3-pentyl)oxy]aluminohydride (LiTEPA)¹⁸to afford

the corresponding primary alcohol. Silylation, followed

by Peterson methylenation/desilylation gave 10.

Deprotection-reprotection of the phenol group on

intermediate tertiary alcohol 11 prior to introduction

of the exo-methylene group was accomplished in a one-

step procedure by treatment with tetra-n-butylammo-

nium fluoride (TBAF) and acetic anhydride (Scheme 3).

Subsequent elimination of TMSOH provided diene 12.

Regioselective cyclopropanation of 12 using diethylzinc

and chloroiodomethane¹⁹provided spirocyclopropyl de-

rivative 13.

Compound 16 was prepared by treatment of the

lithium enolate of 3-ethoxy-5,5-dimethyl-2-cyclohex-

enone with bromide 5 affording 14 (Scheme 4). Enone

transpositioning was accomplished using methyllithium,

followed by Peterson methylenation to give the desired

diene 16, isomeric to 8c.

Compound 19 was prepared from isophorone and

allylic bromide 18, followed by methylenation and

deprotection (Scheme 5). Bromide 18 was prepared in

a straightforward fashion by Horner-Emmons reaction

of aldehyde 4b with methyl (dimethylphosphono)ac-

structural framework of the cyclocymopols was designed

to allow for flexibility in the construction of diverse

analogues. This strategy was retrosynthetically based

on dissection of the molecule into electrophilic aromatic

and nucleophilic aliphatic fragments, each readily ame-

nable to variation prior to coupling through enolate

alkylation chemistry. Electrophilic benzyl bromide 5

was prepared in multigram quantities in three steps

from the known 4-bromo-2-hydroxy-5-methoxybenzal-

dehyde (4a )¹²(Scheme 1). This was accomplished by

silylation of the phenol, followed by sodium borohydride

reduction of the aldehyde and conversion of the result-

ant benzylic alcohol to the corresponding bromide using

triphenylphosphine dibromide.¹³

The general synthetic route for cyclocymopol analogue

synthesis is outlined in Scheme 2. The lithium enolate

of 5,5-dimethyl-2-cyclohexenone (6a ) was trapped with

benzyl bromide 5 to provide the key intermediate enone

7a . An alternate route to this intermediate through

TMSCl-assisted conjugate addition of lithiomethyl cy-

anocuprate to 3-methyl-2-cyclohexenone, followed by

Lewis acid-mediated (TiCl₄or BF₃‚OEt₂) alkylation¹⁴of

the intermediate silyl-enol ether with benzyl bromide

5, failed to give the desired product in a synthetically

useful yield. While the lithium enolates reacted slowly

at room temperature, these metalated enolate species

most likely lacked sufficient reactivity to overcome steric

congestion around the neopentyl carbon. Catalytic

hydrogenation of enone 7a , followed by Peterson meth-

ylenation¹⁵of the resultant ketone, gave 8a (Wittig

methylenation failed to give the desired product). Me-

1780 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9

Hamann et al.

Sch em e 5^a

Sch em e 7^a

(a) Methyl (dimethylphosphono)acetate, NaH, PhH, rt; (b)

DIBAL-H, THF, -78 °C; (c) Ph₃P, Br₂, DMF, 0 °C.

Sch em e 6^a

(a) n-Bu₃SnH, AIBN, PhH, rt; (b) TBAF, THF, rt; (c) SeO₂,

CH₂Cl₂, t-BuOOH; (d) Dess-Martin periodinane, CH₂Cl₂; (e) MeLi,

THF, -78 °C; (f) Burgess reagent, PhH, rt; (g) TBAF, THF, Ac₂O,

0 °C.

Sch em e 8^a

(a) TMSCH₂Li, THF, -78 °C; (b) HF/py, THF, rt; (c) Tebbe’s

reagent, THF/tol, 0 °C; (d) SeO₂, t-BuOOH, CH₂Cl₂, rt.

etate, affording cinnamate 17. Reduction of 17 with

DIBAL-H and subsequent bromination of the resultant

primary allylic alcohol gave 18.

The use of Tebbe’s reagent²⁰was required to prepare

compound 22a from 20a (Scheme 6), as attempted

Peterson methylenation gave a low yield (16%) of the

product of bis-addition, 21. Allylic oxidation²¹of 22a

afforded a low yield (14%) of the corresponding tertiary

alcohol 23. Compound 22b was prepared in two steps.

The reaction of the lithium enolate of isophorone with

p-nitrobenzene disulfide gave intermediate 20b, which

required the use of Tebbe’s reagent for conversion to

22b, giving the desired product in low yield.

Analogue 24 was prepared using the route described

for 8c, starting with isophorone and the corresponding

benzylic bromide, prepared by bromination of 5-meth-

ylbenzofurazan with NBS.

(a) 2.2 equiv of LDA, THF/HMPA, -35 °C; (b) 5, THF, -35

°C; (c) CaCO₃, CCl₄, 65 °C; (d) H₂, 10% Pd on C, EtOAc; (e)

TMSCH₂Li, THF, -78 °C; (f) HF/py, THF, rt; (g) MeMgBr, CuI,

Et₂O, 0 °C; (h) g, then PhSeBr, 0 °C; (j) H₂O₂(aq), CH₂Cl₂, 35 °C;

(k) TBAF, Ac₂O, THF, 0 °C.

mixture of diastereomeric tertiary alcohols, which upon

elimination using Burgess’ reagent²³gave, after desi-

lylation/acetylation, 31.

In addition to those enantiomerically-pure analogues

arrived at through semisynthesis, several optically-pure

analogues (34-36) were synthesized through total

synthetic approaches (Scheme 8). The pivotal interme-

diate in the synthesis of 34a , enone 33a , was prepared

in four steps from commercial (R)-3-methylcyclohex-

anone. The first two steps used the same procedure as

for the preparation of 8. The dianion²⁴of 32a was

treated with benzylic bromide 5, affording a benzylated

â-keto sulfoxide which was subjected to dehydrosulfe-

nylation to produce enone 33a . Enantiomer 34b was

synthesized using the same route, starting with (S)-3-

All semisynthetic compounds were prepared from

silyl-protected natural cyclocymopols 25a and 25b.

Completely selective aliphatic debromination of each

independent diastereomer followed by desilylation af-

forded the respective enantiomers 26b and 27b (Scheme

7). Compound 28b was prepared by allylic oxidation of

26a , affording a readily separable diastereomeric mix-

ture of allylic alcohols, followed by desilylation. Oxida-

tion of the diastereomeric mixture was achieved using

Dess-Martin periodinane²²which afforded enone 29.

Methyllithium addition to the enone gave a separable

Novel Nonsterodial Progesterone Receptor Antagonists

J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9 1781

Ta ble 1. Activities of Nonsteroidal Compounds on hPR-B1 in

these nonsteroidal PR antagonists inhibit a progester-

one-mediated response in a concentration-dependent

manner.

Cotransfected CV-1 Cells^a

agonist

antagonist

efficacy^b

(%)

potency^c

EC₅₀(nM)

efficacy^b

(%)

potency

IC₅₀(nM)

Cross-reactivities with other IRs were assessed by

determining the activities as agonists or antagonists of

hGR,^6dhAR,^6chuman mineralocorticoid receptor (hMR),^6e

and human estrogen receptor (hER)^6fin cotransfection

assays (Table 2). Unlike the steroidal PR antagonists,

none of the nonsteroidal PR antagonist analogues were

agonists in cotransfection assays using hGR, hAR, hMR,

or hER. A few analogues in this series were weak

antagonists only of hAR in cotransfection assays, but

demonstrated no appreciable hER, hGR, or MR antago-

nist activities.

compound

RU486

ZK98,299

22a

22b

na^d

84 ( 7

39 ( 2

96 ( 1

99 ( 0

83 ( 3

0.18 ( 0.02

1.60 ( 0.35

549 ( 55

35 ( 2

4020 ( 230 55 ( 9

71 ( 5

405 ( 93

783 ( 83

3567 ( 2247

1200

25 ( 9

1295 ( 283 37 ( 8

98^e

115^e

ND^f

23^e

72^e

458

87^e

3300

710

160

580

3300

1800 ( 0

1050 ( 235

1457

2117

42^e

26^e

Recep tor Bin d in g Assa ys. Binding K_ivalues were

determined using baculovirus expressed²⁶hPR-A to

provide information about the interaction of a molecule

with the receptor independent of issues such as distri-

bution, metabolism, and protein binding and are sum-

marized in Table 3. Binding affinities to baculovirus

expressed hGR, hAR, and hER were also determined

to evaluate the potential for cross-reactivities involving

these receptors.

66^e

50 ( 8

61^e

85 ( 4

90 ( 3

44 ( 23 1350 ( 71

87 ( 1

72 ( 1

94 ( 1

260 ( 62

1950 ( 1200

741 ( 98

597 ( 206

3400

27a

27b

28b

3264 ( 358 45 ( 5

73^e

78^e

2000

660

T-47D Alk a lin e P h osp h a ta se Assa ys. The T-47D

cell line is derived from a human breast cancer.²⁷It

expresses both endogenous wild-type human PR iso-

forms (hPR-A and hPR-B). This cellular context may

therefore allow observation of biological properties of

these analogues distinct from those observed using the

cotransfection assay with hPR-B1.²⁸Incubation of

T-47D cells with PR agonists stimulates expression of

alkaline phosphatase. Table 4 summarizes the IC₅₀

values for a selection of PR antagonist analogues in the

T-47D alkaline phosphatase assay. The nonsteroidal

PR antagonist analogues were devoid of agonist proper-

ties and, consistent with the cotransfection assay data,

inhibited progesterone-induced alkaline phosphatase

expression in a concentration-dependent manner.

83^e

34a

34b

93 ( 4

62 ( 4

1050 ( 495

320 ( 93

350 ( 14

985 ( 615

2443

42^e

3011

63 ( 11 3005 ( 849 52 ( 1

63 ( 19

93^e

Values represent triplicate determinations. ^bAgonist efficacies

relative to progesterone (100%), antagonist efficacies determined

as percent of maximal inhibition. ^cEC₅₀/IC₅₀values calculated as

the concentration of ligand required to give half-maximal activa-

tion/inhibition, respectively. Not active; defined as efficacy <20%,

potency >10 000 nM. ^eAssayed once. ^fNot determined.

methylcyclohexanone, which was accessible from (S)-

pulegone by a retro aldol reaction.²⁵Compounds 35 and

36 were prepared from 33a . Diene 35 was prepared by

methyl cuprate addition, followed by trapping of the

enolate with phenylselenenyl bromide to afford the

phenylselenenoketone intermediate, which was elimi-

nated using hydrogen peroxide in pyridine. Conversion

of this intermediate as previously described yielded 35.

Compound 36 was prepared from 33a as previously

described for 9.

Decid u a liza tion Assa y in Mice. To further estab-

lish this pharmacophore as a structurally novel PR

antagonist lead, some of the more potent analogues

underwent limited in vivo testing using a murine

uterine decidualization assay. A successful pregnancy

requires not only fusion of egg and spermatozoon, but

also the provision of a receptive and supportive uterus.

During early pregnancy (days 3-6) in mice, there is a

steep increase in progesterone concentrations in the

circulation, which peaks at about 30 ng/mL on day 6,

whereas 17â-estradiol concentrations remain relatively

constant during the same period.²⁹This endocrine

profile coincides with the window during which the

uterus undergoes an important transformation, i.e.,

decidualization, in order to provide a receptive and

supportive environment for blastocyst implantation.

Progesterone acts upon the estrogen-primed uterus to

facilitate this process.³⁰

Biologica l Resu lts a n d Discu ssion

Cotr a n sfection Assa ys. Using the cotransfection

assay, specific ligand-dependent modulation of gene

transcription by individual IRs can be studied experi-

mentally. This assay is thus an effective tool for

functional characterization of the interactions of small

molecule agonists or antagonists with hPR. In the

cotransfection assay, progesterone causes a concentra-

tion-dependent increase of reporter gene (luciferase)

activity that can be reversed by PR antagonists. The

cotransfection assays used to measure antagonist activ-

ity utilized a modification of hPR-B, hPR-B1,^6a,bthe

results of which are summarized in Table 1. The

nonsteroidal PR antagonist analogues do not possess

intrinsic hPR agonist activity. Antagonist effects on

hPR-B1 were determined by evaluating compounds in

the presence of progesterone at 1 nM, its EC₅₀. The

hPR-B1 cotransfection assay data demonstrate that

Pseudopregnant mice (fertile females mated with

vasectomized males) were used to establish the assay

system. These in vivo experiments were designed to

utilize the high concentrations of endogenous progest-

erone present during early days of pseudopregnancy and

then induce uterine decidualization with an artificial

stimulus (oil).³¹Subsequent manipulation of the endo-

crine status was achieved by perturbing progesterone

action with various PR antagonists in an attempt to

1782 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9

Hamann et al.

Ta ble 2. Antagonist^aCross-Reactivities on hAR, hER, hGR, and hMR^a

IC₅₀(nM) [efficacy^b(%)]

hER

compound

hAR

hGR

hMR

progesterone

RU486

ZK98,299

22a

27a

37 ( 2 [46 ( 7]

5 ( 2 [75 ( 2]

269 ( 57 [93 ( 4]

449 ( 69 [79 ( 8]

238 ( 123 [89 ( 3]

250 [21]^e

>1000 [<20]

>1000 [39 ( 8]

14 ( 4 [83 ( 6]

>1000 [40 ( 7]

0.8 ( 0.1 [98 ( 1]

>1000 [77 ( 5]

>1000 [34 ( 9]

ND^d

>1000 [27 ( 4]

27 ( 4 [100 ( 0]

na^c

377 ( 49 [90 ( 1]

1500 [40]^e

Values represent triplicate determinations. Antagonist efficacies were determined as a function (%) of maximal inhibition in the

presence of an EC₅₀concentration of DHT, estradiol, dexamethasone, or aldosterone for hAR, hER, hGR, and hMR, respectively. ^cNot

active; defined as efficacy <20%, potency >10 000 nM. Not determined. ^eAssayed once.

Ta ble 3. Binding Affinities for hPR-A, hGR, hAR, and hER

K_i: mean (nM) ( SEM

Ta ble 4. Antagonist Efficacies and Potencies in the T-47D

Alkaline Phosphatase Assay^a

compound

efficacy^b(%)

potency^cIC₅₀(nM)

compound

hPR-A

hGR^a

hAR

hER

RU486

ZK98,299

22a

22b

83 ( 9

91 ( 4

84 ( 5

66 ( 12

72 ( 1

72^d

0.35 ( 0.15

3.2 ( 0.3

354 ( 70

3500 ( 350

163 ( 24

280

progesterone

3.5 ( 0.2

30.5 ( 1.9

5.2 ( 1.2

8.5 ( 3.1

1.1 ( 0.3

na^c

0.38 ( 0.11

dexamethasone ND^b

DHT

estradiol

RU486

ZK98,299

0.58 ( 0.07 0.68 ( 0.06 10.6 ( 2.9

18 ( 3

41.8 ( 4.6

3210 ( 486 ND

2465 ( 412 ND

2206 ( 333 1542 ( 239 ND

2781 ( 499 1518 ( 8.9 ND

1261 ( 114 1449 ( 167 ND

4532 ( 369 1923 ( 273 ND

1036 ( 14

>100

26^d

1200

490 ( 30

343 ( 23

77 ( 5

156 ( 4

31 ( 2.5

441 ( 58

22 ( 3

75 ( 8

250 ( 25

>10000

2000

<20

73^d

59^d

770

440

1300

1600

68^d

75^d

696 ( 136

65^d

3247 ( 480 6386 ( 562 6810 ( 3199 ND

59.6 ( 2.7 2199 ( 235 1942 ( 1492 ND

98 ( 11

109 ( 14

84 ( 12

28.8 ( 0.8 6812 ( 437 2698 ( 1748 ND

53.5 ( 1.2 5424 ( 679 6303 ( 3708 na

119 ( 21

243 ( 39

88 ( 7

218 ( 23

34 ( 5.8

275 ( 21

455 ( 38

71 ( 9

69 ( 8

21 ( 3

84 ( 7

81^d

510

2570 ( 578 3008 ( 484 ND

2670 ( 678 1591 ( 346 ND

4417 ( 785 2318 ( 354 ND

80 ( 3

89 ( 2

81 ( 4

71 ( 3

85 ( 5

51 ( 0

83^d

186 ( 42

420 ( 15

94 ( 6

775 ( 325

210 ( 58

290 ( 20

1700

430

210

300

200

22a

22b

27a

27b

28b

8215 ( 1785 na

8511 ( 1489 6454 ( 3556 ND

8356 ( 1644 na

81^d

27a

27b

28b

1766 ( 142 737 ( 195

81^d

1777 ( 166 1099 ( 736 ND

34a

34b

85^d

63^d

6662 ( 3348 ND

50 ( 10

65 ( 1

147 ( 48

350 ( 50

4109 ( 757 6387 ( 3623 ND

34a

34b

3697 ( 571 1644 ( 135 ND

2286 ( 242 570 ( 177

Values represent triplicate determinations. Efficacies were

2379 ( 734 1497 ( 905 ND

determined as a function (%) of maximal inhibition. ^cIC₅₀values

were calculated as the concentration of ligand required to give half-

1657 ( 1043 1139 ( 32

na na

maximal inhibition in the presence of progesterone at its EC₅₀

Assayed once.

GR prepared from CV-1 extract. Not determined. ^cK_i

10 000 nM.

block oil-induced decidual cell reaction. Percent inhibi-

tion was estimated using the following formula:

% inhibition )

weight gain in treated group

weight gain in control group

100 -

× 100

As shown in Figure 1, control mice showed a dramatic

increase in net uterine wet weight gain (323.8 ( 27.6

mg) in response to the decidual stimulus. RU486

completely blocked this response at a dose of 0.5 mg/

day orally or 0.1 mg/day intraluminally (Figure 2),

resulting in net increases of only 1.0% (3.2 ( 1.0 mg) of

the control value (estimated ED₅₀for RU486 ) 0.05 mg).

Block of Decid u a liza tion by 22a a n d 27a . Figures

2 and 3 show that both 22a and 27a block oil-induced

decidualization. Compound 27a showed no efficacy at

1.0 mg/day (data not shown), but blocked decidualiza-

tion by 85% when given at a dose of 5.0 mg/day.

Compound 22a showed comparable potency, inhibiting

deciduomata formation by 80% at a dose of 5.0 mg/day.

F igu r e 1. Effect of RU486 on oil-induced uterine decidual-

ization when given orally once daily for three days (day 3 to

day 5 of pseudopregnancy); *p < 0.05; ***p < 0.001 vs control.

Number of mice is given in parentheses.

The PR antagonist RU486 was highly effective in

blocking deciduomata formation, indicating that the

endometrial sensitivity was greatly reduced by this

Novel Nonsterodial Progesterone Receptor Antagonists

J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9 1783

natural product lead compounds. By removal of the

aliphatic bromine in each of the respective natural

cyclocymopols (1 and 2), the resultant optically-pure

forms of previously-synthesized racemate 8a (27a and

27b) were prepared and were observed to exhibit

enhanced PR antagonist activity relative to that of the

parent compounds. Interestingly, analysis of the cotrans-

fection assay data for these three analogues indicates

that while the parent natural product with the 3(S)

configuration (2) displayed full agonist properties, the

debromo analogue (27b) had only weak yet measurable

partial agonist properties, and instead exhibited an-

tagonist properties with slightly greater potency than

its enantiomer (27a ). On the basis of biological data

for these and related analogues, it appears that the

absolute stereochemistry at C₃is of lesser significance

relative to the biological activity than the conforma-

tional orientation of the benzylic moiety with respect

to the aliphatic ring. Use of molecular modeling helped

to elucidate the preferred conformation of the benzylic

group about the cyclohexyl ring. Structures were

minimized using the Quanta interface to the CHARMM

force field with the conjugate gradient minimization

method. The axial conformation was calculated to be

favored by approximately 4 kcal/mol, due to unfavorable

van der Waals interactions (allylic strain) with the

methylidene group.³⁶Substituents at the other neo-

pentyl position on the cyclohexyl ring (C₁in parent

compounds 1 and 2) can exert a counterinfluence to this

conformational preference to avoid unfavorable 1,3-

diaxial interactions. Since antagonist activity was

generally superior in analogues without the aliphatic

bromine, and this allows the molecule to adopt a more

energetically favorable conformation, analogues without

substitution at this position or with substituents trans

to the benzylic substituent were generally pursued.

F igu r e 2. Effect of RU486 (0.10 mg, intrauterine), 27a (5 mg

intrauterine), and 37 (5.0 mg intrauterine) on oil-induced

uterine decidualization (single dose, day 4 of pseudopregnancy)

in BALB/c mice; **p < 0.01 vs control. Numbers of mice in

each group are given in parentheses.

F igu r e 3. Effect of RU486 (0.10 mg, intrauterine) and 22a

(2.5 and 5.0 mg intrauterine) on oil-induced uterine decidu-

alization (single dose, day 4 of pseudopregnancy) in ICR mice;

**p < 0.01 vs control. Numbers of mice in each group are given

in parentheses.

The diene 8c, with an aliphatic portion derived from

isophorone, showed a substantial improvement in bind-

ing affinity to hPR-A (K_i) 31 nM) relative to the parent

compounds 1 and 2, yet was weakly active in the

cotransfection assay (IC₅₀) 3567 nM). Relative to

binding assays which are performed using a cell-free

receptor preparation, the cotransfection assay more

closely mimics an in vivo setting, where components of

the intact cell have the potential to metabolize test

compounds. Additionally, the cotransfection assays are

typically of 40 h duration at physiologic temperature

(37 °C), as compared with binding assays performed at

4 °C for 16 h. Compound instability under the cotrans-

fection assay conditions was suspected to be a potential

cause of the disparity in data obtained in these two

assays, and studies were therefore undertaken to ex-

amine this possibility. The two most likely sources of

chemical instability of these analogues were ad-

dressed: unwanted cyclization of the phenol group onto

the exo-methylene under mildly acidic conditions to yield

inactive compounds with cymobarbatol³⁷skeleton 38 (eq

1) and oxidation of the p-methoxyphenol to an inactive

quinone.³⁸

compound. The ability of RU486 to prevent uterine

responses to various stimuli has also been shown in

rats,³²monkeys,³³and ewes.³⁴Vinijsanun and Martin³⁵

have demonstrated further that the inhibitory effects

of RU486 and another anti-progestin, ZK98,734, on

mouse uterine decidualization were restricted to the

actions mediated by progesterone. Like RU486, the two

nonsteroidal PR modulators tested in this assay dis-

played pharmacologically effective PR antagonist activi-

ties in vivo. Both compounds blocked mouse uterine

decidualization in a dose-dependent manner, and the

effect was nearly maximal at 5.0 mg/day. A third

compound, 37, which is structurally similar yet inactive

in cotransfection and binding assays, was also examined

in this model; this was to rule out the possibility that

in vivo activity of these compounds was due to toxicity

at the doses given. The control compound (37) did not

block decidualization, consistent with the inactivity

observed using in vitro assays.

Discu ssion of Str u ctu r e-Activity Rela tion sh ip s

Initial synthetic studies focused both on total syn-

thetic and semisynthetic approaches to analogues of the

1784 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9

Hamann et al.

data are reported in the following manner: chemical shift,

multiplicity, coupling constants, and assignment. Infrared (IR)

spectra were recorded on a Mattson Galaxy Series 3000 FT

infrared spectrometer. Liquid samples were measured as neat

films on NaCl plates; solid samples were measured as KBr

pellets. The reported frequencies are given in reciprocal

centimeters (cm^-1) with the following relative intensities: s

(strong, 70-100%), m (medium, 40-70%), w (weak, 20-40%),

br (broad). Optical rotations were obtained on a Perkin-Elmer

241 polarimeter using a cell 1 dm in length and are reported

This cyclization, observed in certain analogues to

occur to a measurable extent under the conditions of

the cotransfection assay, also occurs in nature, as

compounds of the general cymobarbatol structure are

also present in some algal extracts containing the

cyclocymopols. In particular, the cymobarbatol com-

pound corresponding to 8c was isolated in approxi-

mately 30% from the cotransfection assay medium upon

incubation of 8c for 40 h at 37 °C (results not shown).

Structural features present in 8c and other diene

analogues can stabilize a positive charge at C₁in the

transition state leading to cymobarbatol formation to a

greater degree than the parent compounds, due to allylic

delocalization.

To circumvent issues of chemical instability, several

analogues were synthesized with the intent of finding

biologically suitable replacements for both the phenol-

substituted aryl group and the exo-methylene group. A

systematic examination of varied aryl groups resulted

in the observation that a p-nitrophenyl group could

replace the aryl group of the natural cyclocymopols

without loss of activity, giving active structures typified

by 22a . This substitution greatly simplified the syn-

thetic route to analogues of this type and also eliminated

the possibility for phenolic oxidation. In general, elec-

tron-deficient aryl groups (Ar ) p-nitrophenyl, p-bro-

mophenyl, p-acetylphenyl) exerted a beneficial influence

on activity as compared with electron-rich aryl groups

(Ar ) p-methoxyphenyl, p-dimethylaminophenyl, m-

methoxyphenyl). Parallel to these efforts, it was also

discovered that a spirocyclopropyl group could function

as a bioisosteric surrogate³⁹for the exo-methylene unit

(13) without loss of activity, yet other substitutions for

this exo-olefin (i.e. ketone, hydroxyl, methyl) destroyed

activity.

as follows: [R]^temp

(concentration in g/100 mL, solvent).

wavelength

Elemental analyses were performed by Oneida Research

Services, Inc., Whitesboro, NY, or Galbraith Laboratories, Inc.,

Knoxville, TN. Flash column chromatography refers to the

method of Still⁴⁰using Merck 230-400 mesh silica gel.

Gradient elution refers to applying the compound as a solution

in hexanes to the hexanes-equilibrated column and then

eluting with progressively more polar hexanes/EtOAc solu-

tions. Analytical thin layer chromatography (TLC) was per-

formed using Merck 60-F-254 0.25 mm precoated silica gel

plates. Compounds were visualized using ultraviolet light,

iodine vapor, or cerium molybdate/sulfuric acid/methanol.

Preparative thin layer chromatography (PTLC) was performed

using Merck 60-F-254 0.50 or 1.00 mm precoated silica gel

plates. High-performance liquid chromatography (HPLC) was

performed on a Beckman System Gold 126 chromatograph

using a 4.6 × 250 mm Beckman Ultrasphere ODS column.

Preparative HPLC was performed on a Waters Delta Prep

4000. The detector wavelength was set to 254 nm. Ethyl ether

and tetrahydrofuran were distilled directly prior to use from

sodium/benzophenone ketyl. Dichloromethane (CH₂Cl₂), ben-

zene, and toluene were dried and stored under nitrogen over

4 Å molecular sieves. Organic amines were distilled from

CaH₂and stored over solid KOH pellets under nitrogen.

Unless otherwise specified, solutions of common inorganic salts

used in workups are aqueous solutions. All moisture sensitive

reactions were carried out using oven-dried or flame-dried

round-bottomed (rb) flasks and glassware under an atmo-

sphere of dry nitrogen.

Gen er a l P r oced u r e for Cycloa lk en on e Alk yla tion w ith

Ben zylic or Allylic Ha lid es. 6-[[4-Br om o-2-[(ter t-b u -

t yld im et h ylsilyl)oxy]-5-m et h oxyp h en yl]m et h yl]-5,5-d i-

m eth ylcycloh ex-2-en -1-on e (7a ). To a flame-dried 50-mL

rb flask containing diisopropylamine (0.19 mL, 1.3 mmol, 1.1

equiv) in 10 mL of THF at -78 °C was added n-BuLi (0.58

mL of a 2.2 M solution in hexanes, 1.3 mmol, 1.1 equiv). After

20 min at -78 °C, enone 6a (0.15 g, 1.2 mmol) was added as

a solution in 1 mL of THF, and the reaction mixture was

allowed to stir at -78 °C for 15 min before removal of the

cooling bath. When the temperature of the reaction mixture

reached -5 °C, benzylic bromide 5 (1.00 g, 2.44 mmol, 2.00

equiv) was added as a solution in 2 mL of THF. The reaction

mixture was then allowed to warm to room temperature (rt),

and after 3 h, TLC analysis indicated complete consumption

of the enone starting material and the formation of a less polar

product (R_f0.59, 2:1 hexanes/EtOAc), and the reaction was

quenched by the addition of 5 mL of saturated NH₄Cl. The

contents of the flask were transferred to a separatory funnel

and extracted with 60 mL of EtOAc, and the resultant organic

phase was washed with 30 mL of brine, dried (Na₂SO₄), and

concentrated under reduced pressure. Purification by flash

column chromatography (silica gel, hexanes/EtOAc, gradient

elution) afforded 0.459 g (83%) of the benzylated enone as a

colorless low-melting solid: ¹H NMR 0.21 and 0.23 [2s, 2 ×

3H, Si(CH₃)₂], 0.99 [s, 9H, SiC(CH₃)₃], 1.02 and 1.03 (2s, 2 ×

3H, geminal CH₃’s), 2.25 and 2.32 (dd of AB q, 2H, J _AB) 20.0,

J _A) 3.9, 2.0, J _B) 4.1, 2.2, 4-H), 2.51 (dd, 1H, J ) 8.7, 5.0,

Con clu sion

We have synthesized PR antagonists of a novel

structural type which contribute to our understanding

of key molecular features critical for development of

more potent, highly selective PR antagonists. Relative

to the parent compounds, the synthetic nonsteroidal PR

antagonist analogues have been observed to exhibit

improved binding affinities for hPR-A and an enhance-

ment in the ability to repress PR-mediated gene expres-

sion in the hPR-B1 cotransfection assay in CV-1 cells.

The compounds displayed moderate cross-reactivity as

antagonists of hAR, but were not antagonists or agonists

in cotransfection assays using hER, hGR, or hMR. The

binding affinities of these analogues were selective for

hPR relative to other IRs. In addition, compounds in

this series of analogues were shown to possess PR

antagonist activity in vivo. The structure-activity

relationships around this pharmacophore elucidated to

date have demonstrated that these compounds can serve

as a useful template to prepare more potent and

selective PR antagonists.

6-H), 2.78 and 2.88 (d of AB q, 2H, J _AB) 14.2, J _A) 8.7, J _B

)

Exp er im en ta l Section

5.1, benzylic CH₂), 3.80 (s, 3H, OCH₃), 5.96 (ddd, 1H, J ) 10.0,

2.1, 1.9, 2-H), 6.68 (s, 1H, 6′-H), 6.77 (ddd, 1H, J ) 9.9, 4.1,

3.8, 3-H), 6.94 (s, 1H, 3′-H); ¹³C NMR -4.0, 18.4, 24.4, 25.9,

26.1, 28.6, 37.1, 39.5, 56.8, 58.3, 108.4, 114.4, 123.1, 128.5,

131.2, 146.3, 147.6, 150.1, 201.7.

Gen er a l Ch em ica l P r oced u r es. Proton nuclear magnetic

resonance (¹H NMR) and carbon-13 nuclear magnetic reso-

nance (¹³C NMR) spectra were recorded with CDCl₃as the

solvent at 400 and 100 MHz, respectively (Bru¨ker AC 400).

Chemical shifts are given in parts per million (ppm) downfield

from internal reference tetramethylsilane in δ units, and

coupling constants (J values) are given in hertz (Hz). Selected

Gen er a l P r oced u r e for En on e CdC Bon d Red u ction .

2-[[4-Bromo-2-[(tert-butyldimethylsilyl)oxy]-5-methoxyphenyl]-

methyl]-3,3-dimethylcyclohexan-1-one. To a flame-dried 100-

Novel Nonsterodial Progesterone Receptor Antagonists

J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9 1785

mL rb flask containing enone 7a (0.154 g, 0.454 mmol) in 22

mL of EtOAc (predried over K₂CO₃) at rt was added 20 mg of

5% palladium on carbon (ca. 2 mol %), and after flushing/

evacuating the vessel three times with nitrogen, a hydrogen

atmosphere was introduced and maintained by use of a

balloon. After 24 h, the flask was again flushed several times

with nitrogen, and the contents of the flask were filtered,

rinsing with an additional 100 mL of EtOAc. Rotary evapora-

tion of the solvent afforded 0.156 g (99%) of the saturated

ketone as a colorless syrup (R_f0.67, 2:1 hexanes/EtOAc): ¹H

NMR 0.22 and 0.25 [2s, 2 × 3H, Si(CH₃)₂], 0.87 and 1.12 (2s,

2 × 3H, geminal CH₃’s), 1.01 [s, 9H, SiC(CH₃)₃], 1.61-1.95

(m, 4H, 4,5-H), 2.19-2.38 (m, 2H, 6-H), 2.67 and 2.88 (dd of

AB q, 2H, J _AB) 14.0, J _A) 6.1, 3.1, J _B) 9.8, 0, benzylic CH₂),

3.71 (s, 3H, OCH₃), 6.79 (s, 1H, 6′-H), 6.91 (s, 1H, 3′-H).

Gen er a l P r oced u r e for P et er son Met h ylen a t ion of

Keton es. 2-[(4-Br om o-2-h ydr oxy-5-m eth oxyph en yl)m eth -

yl]-3,3-d im eth yl-1-m eth ylid en ecycloh exa n e (8a ). To a

flame-dried 50-mL rb flask containing 2-[[4-bromo-2-[(tert-

butyldimethylsilyl)oxy]-5-methoxyphenyl]methyl]-3,3-dimeth-

ylcyclohexanone (0.13 g, 0.28 mmol) in 5 mL of THF at -78

°C was added [(trimethylsilyl)methyl]lithium (0.42 mL of a 1.0

M solution in pentane, 0.42 mmol, 1.5 equiv). An immediate

change from colorless to a yellow reaction solution was

observed, and TLC analysis indicated complete consumption

of starting material and the formation of a less polar product

(R_f0.79, 2:1 hexanes/EtOAc). The reaction was then quenched

with 4 mL of saturated NH₄Cl. EtOAc (30 mL) extraction of

the reaction mixture, drying (Na₂SO₄), and concentration

under reduced pressure gave 0.152 g (99%) of a crude product,

which was a single diastereomer of the ketone addition product

by ¹H NMR analysis. A portion of this crude intermediate

(0.015 g, 0.028 mmol) was placed in a 10-mL Nalgene vial

containing 2 mL of THF, 0.2 mL of HF/pyridine complex was

added, and the mixture was allowed to stir at rt for 32 h, at

which time TLC analysis indicated complete consumption of

starting material and formation of a more polar product. The

contents of the reaction vessel were transferred to a separatory

funnel containing 20 mL EtOAc and 10 mL 1.0 M NaHSO₄.

The layers were separated, and the resultant organic phase

was washed with 10 mL brine, dried (Na₂SO₄), and concen-

trated under reduced pressure. Purification by flash column

chromatography (silica gel, hexanes/EtOAc, gradient elution)

afforded 8.7 mg (92%) of the phenolic olefin as a colorless oil:

¹H NMR 0.97 and 1.00 (2s, 2 × 3H, geminal CH₃’s), 1.25-

1.35 (m, 1H, 5-H), 1.53-1.64 (m, 3H, 4,5-H), 2.05 (ddd, 1H, J

) 12.9, 8.7, 4.3, 6-H_ax), 2.12 (dd, 1H, J ) 10.9, 3.9, 2-H), 2.21-

2.28 (m, 1H, 6-H_eq), 2.65 and 2.80 (d of AB q, 2H, J _AB) 14.1,

J _A) 10.9, J _B) 3.5, benzylic CH₂), 3.80 (s, 3H, OCH₃), 4.36

(d, 1H, J ) 1.0) and 4.63 (s, 1H) [methylidene CH₂], 6.59 (s,

1H, 6′-H), 6.94 (s, 1H, 3′-H); ¹³C NMR 23.5, 26.7, 28.1, 28.4,

32.4, 35.2, 36.1, 54.3, 57.0, 108.3, 110.3, 115.0, 120.1, 128.8,

148.0, 148.5, 150.0; IR (neat) 3437 (br, m); HRMS calcd for

C₁₇H₂₃BrO₂m/z 338.0882, found m/z 338.0867.

Gen er a l P r oced u r e for P et er son Met h ylen a t ion of

En on es. 6-[(4-Br om o-2-h yd r oxy-5-m eth oxyp h en yl)m eth -

yl]-5,5-d im eth yl-1-m eth ylid en ecycloh ex-2-en e (8b). This

compound was prepared from enone 7a (0.075 g, 0.17 mmol)

in the manner previously described for olefin 8a , with the

following procedural changes. After formation of the initial

[(trimethylsilyl)methyl]lithium addition adduct to enone 7a ,

the phenolic protecting group was exchanged prior to effecting

elimination of TMSOH. The crude addition product (0.090 g,

0.17 mmol) was dissolved in 5 mL of THF containing 0.20 mL

of acetic anhydride (2.1 mmol) and cooled to 0 °C. Tetra-n-

butylammonium fluoride (0.20 mL of a 1.0 M solution in THF,

0.20 mmol, 1.2 equiv) was added, and the mixture was allowed

to warm to rt. The contents of the flask were then poured

into a separatory funnel containing 30 mL of EtOAc and 10

mL of 1.0 M NaHSO₄, the layers were separated, and the

organic phase was washed with 10 mL brine, dried (Na₂SO₄),

and concentrated under reduced pressure. The crude material

thus obtained was transferred to a 10 mL nalgene vial

containing 3 mL of THF, and 0.3 mL of HF/pyridine complex

was added. After stirring overnight at rt, the reaction mixture

was worked up as previously described, and purification by

flash column chromatography (silica gel, hexanes/EtOAc,

gradient elution) afforded 38 mg (64%) of the desired acetoxy

diene as a colorless, low-melting solid: ¹H NMR 0.89 and 1.11

(2s, 2 × 3H, geminal CH₃’s), 1.84 and 2.13 (d of AB q, 2H, J _AB

) 18.6, J _A) 5.4, J _B) 0, 4-H), 2.27 (s, 3H, acetate CH₃), 1.94

and 2.80 (d of AB q, 2H, J _AB) 12.9, J _A) 2.6, J _B) 2.9, benzylic

CH₂), 3.83 (s, 3H, OCH₃), 4.14 and 4.67 (2s, 2 × 1H, CdCH₂),

5.70 (dd, 1H, J ) 7.6, 7.3, 2-H), 6.04 (dd, 1H, J ) 9.8, 0.4,

3-H), 6.52 (s, 1H, 6′-H), 7.19 (s, 1H, 3′-H). The phenolic acetate

was then hydrolyzed under basic conditions to give the desired

phenol. In a 10 mL test tube was combined the above acetate

(10.0 mg, 0.030 mmol) and 2.0 mL of 5% methanolic K₂CO₃.

After 10 min at rt, the methanol was removed by rotary

evaporation, and the residue was dissolved in 20 mL of EtOAc.

The organic solution was then washed with 20 mL of saturated

NH₄Cl, dried (Na₂SO₄), and concentrated under reduced

pressure. Purification by flash column chromatography (silica

gel deactivated with approx. 0.5% triethylamine in hexanes/

EtOAc, gradient elution) afforded 7.1 mg (81%) of the phenolic

diene as a colorless, low-melting solid: ¹H NMR 0.90 and 1.15

(2s, 2 × 3H, geminal CH₃’s), 1.86 and 2.22 (d of AB q, 2H, J _AB

) 18.8, J _A) 5.5, J _B) 0, 4-H), 2.02 and 2.84 (d of AB q, 2H,

J _AB) 11.5, J _A) 3.2, J _B) 3.3, benzylic CH₂), 3.81 (s, 3H,

OCH₃), 4.23 and 4.71 (2s, 2 × 1H, methylidene CH₂), 4.46 (br

s, 1H, OH), 5.78 (dd, 1H, J ) 9.8, 5.2, 2-H), 6.09 (dd, 1H, J )

9.8, 2.3, 3-H), 6.51 (s, 1H, 6′-H), 6.98 (s, 1H, 3′-H); ¹³C NMR

20.8, 25.5, 28.4, 30.8, 36.0, 47.2, 56.2, 108.4, 112.5, 115.0, 122.2,

127.2, 133.0, 134.0, 148.1, 148.5, 152.1.

cis-2-[(4-Br om o-2-h yd r oxy-5-m eth oxyp h en yl)m eth yl]-

3,3,5-tr im eth yl-1-m eth ylid en ecycloh exa n e (9). To a sus-

pension of copper(I) iodide (2 mg) in 1 mL of ether at 0 °C was

added methylmagnesium bromide (0.11 mL of a 3.0 M solution

in ether, 0.32 mmol, 1.0 equiv). Enone 7a (149 mg, 0.320

mmol) in 2 mL of ether was then added slowly while main-

taining the temperature below 5 °C, and upon completion of

the addition, the reaction mixture was stirred at 0 °C for 3 h

before quenching with a 4:1 mixture of saturated NH₄Cl/NH₄-

OH (5 mL). The resultant biphasic mixture was extracted with

50 mL of ether, dried (Na₂SO₄), and concentrated under

reduced pressure. Purification by flash column chromatogra-

phy (silica gel, hexanes/EtOAc, 9:1) afforded 36 mg (30%) of

the desired cis-2-[[4-bromo-2-[(tert-butyldimethylsilyl)oxy]-5-

methoxyphenyl]methyl]-3,3,5-trimethylcyclohexan-1-one as a

colorless, low-melting solid: ¹H NMR 0.22 (s, 6H, Si(CH₃)₂),

1.00 [m, 18H, 3,3,5-CH₃and SiC(CH₃)₃], 1.50 (dd, 2H, J ) 15.1,

6.5, 4-H), 2.02 (m, 1H, 5-H), 2.14 and 2.23 (AB q, 2H, J _AB

)

12.0, 6-H), 2.42 (dd, 1H, J ) 10.4, 6.4, 2-H), 2.88 and 2.89 (d

of AB q, 2H, J _AB) 12.0, J _A) 10.4, J _B) 6.3, benzylic CH₂),

3.82 (s, 3H, OCH₃), 6.65 (s, 1H, 6′-H), 6.92 (s, 1H, 3′-H). This

conjugate addition product (7.50 mg, 0.0200 mmol) was then

methylenated in the manner previously described for 8a ,

affording 2.7 mg (70%) of the desired phenol as a colorless

syrup: ¹H NMR 0.92 and 1.05 (2s, 2 × 3H, geminal CH₃’s),

0.93 (d, 3H, J ) 7.0, 5-CH₃), 1.25 (m, 2H, 4-H), 1.70 (m, 1H,

5-H), 1.85 (dd, 1H, J ) 12.5, 12.5, 6-H_ax), 2.04 (dd, 1H, J )

11.0, 3.4, 2-H), 2.10 (dd, 1H, J ) 13.3, 4.2, 6-H_eq), 2.58 and

2.81 (d of AB q, 2H, J _AB) 13.6, J _A) 11.2, J _B) 3.7, benzylic

CH₂), 3.81 (s, 3H, OCH₃), 4.27 and 4.58 (2s, 2 × 1H, meth-

ylidene CH₂), 4.46 (s, 1H, OH), 6.53 (s, 1H, 6′-H), 6.94 (s, 1H,

3′-H); ¹³C NMR 22.6, 28.4, 28.9, 29.1, 29.3, 34.8, 39.2, 43.1,

54.4, 57.0, 108.3, 111.1, 115.2, 120.2, 128.8, 147.9, 148.4, 149.9;

IR (neat) 3406 (br, s) 2951 (s), 2870 (m), 1496 (s), 1400 (m),

1202 (s). Anal. (C₁₈H₂₇BrO₂) C, H.

cis-2-[(4-Br om o-2-h yd r oxy-5-m eth oxyp h en yl)m eth yl]-

4-(h yd r oxym eth yl)-3,3-d im eth yl-1-m eth ylid en ecycloh ex-

a n e (10). To a suspension of copper(I) bromide/methyl sulfide

complex (57.4 mg, 0.280 mmol, 0.500 equiv) in 3.5 mL of

anhydrous DMS/THF (1:6) at -55 °C was added enone 7a (260

mg, 0.56 mmol) in 2 mL of THF. Vinylmagnesium bromide

(2.79 mL of a 1.0 M solution in THF, 2.79 mmol, 5.00 equiv)

was then added slowly over 1 h while maintaining the

temperature between -50 and -55 °C, and upon completion

of the addition, the reaction mixture was stirred for 1 h before

quenching at 0 °C with 2 N HCl (15 mL). The resultant

biphasic mixture was extracted with 100 mL of EtOAc, dried

(Na₂SO₄), and concentrated under reduced pressure. Purifica-

1786 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9

Hamann et al.

tion by flash column chromatography (silica gel, hexanes/

EtOAc, 9:1) afforded 150 mg (55%) of the desired cis conjugate

addition product as a colorless, low-melting solid, along with

73 mg (27%) of the trans diastereomer: ¹H NMR 0.22 and 0.23

[2s, 2 × 3H, Si(CH₃)₂], 0.99 and 1.07 (2s, 2 × 3H, geminal

CH₃’s), 1.02 [s, 9H, SiC(CH₃)₃], 1.48 (dd, 1H, J ) 13.3, 4.4,

4-H_eq), 1.74 (dd, 1H, J ) 13.4, 12.8, 4-H_ax), 2.16 (dd, 1H, J )

13.3, 4.4, 6-H_eq), 2.35 (dd, 1H, J ) 13.2, 12.8, 6-H_ax), 2.47 (dd,

1H, J ) 11.4, 5.6, 2-H), 2.58 (m, 1H, 5-H), 2.84 and 2.91 (d of

AB q, 2H, J _AB) 14.4, J _A) 5.6, J _B) 11.7, benzylic CH₂), 3.82

(s, 3H, OCH₃), 5.00 (d, 1H, J ) 9.7) and 5.03 (d, 1H, J ) 15.4)

[CHdCH₂], 5.77 (ddd, 1H, J ) 16.9, 10.3, 6.3, CHdCH₂), 6.66

(s, 1H, 6′-H), 6.93 (s, 1H, 3′-H). To a solution of this ketone

(20 mg, 0.04 mmol) in 0.6 mL of 2:1 acetone/water was added

4-methylmorpholine N-oxide hydrate (8 mg, 0.07 mmol, 2

equiv) and osmium tetraoxide (20 µL of a 0.1 M solution in

2-methyl-2-propanol, 0.02 mmol, 0.05 equiv), and the mixture

was stirred at rt for 24 h. The reaction mixture was then

cooled to 0 °C, and NaIO₄(17 mg, 0.081 mmol, 2.0 equiv) in

0.5 mL of water was added. After 3 h of stirring at 0 °C, 0.5

mL of 10% Na₂S₂O₃was added, and the mixture was extracted

with EtOAc (3 × 5 mL). The combined organics were dried

(Na₂SO₄) and concentrated under reduced pressure. Purifica-

tion by flash column chromatography (silica gel, hexanes/

EtOAc, 9:1) afforded 16 mg (81%) of the desired keto aldehyde

as a colorless oil which was used directly in the next step. To

an oven-dried 10 mL rb flask containing aldehyde (55 mg, 0.11

mmol) in 2 mL THF at -78 °C was added LiTEPA (0.26 mL

of a 0.5 M solution in THF, 0.14 mmol, 1.2 equiv). After 4 h

at -78 °C, 0.1 mL of methanol was added, and the reaction

mixture was allowed to warm to rt. Water (1 mL) was added,

and the mixture was extracted with EtOAc (3 × 5 mL). The

combined organics were dried (Na₂SO₄) and concentrated

under reduced pressure. Purification by flash column chro-

matography (silica gel, hexanes/EtOAc, 85:15) afforded 52 mg

(94%) of the desired hydroxy ketone as a colorless oil: ¹H NMR

0.22 and 0.23 [2s, 2 × 3H, Si(CH₃)₂], 0.98 and 1.08 (2s, 2 ×

3H, geminal CH₃’s), 1.01 [s, 9H, SiC(CH₃)₃], 1.47 (m, 1H, 4-H_eq),

1.73 (dd, 1H, J ) 11.5, 11.5, 4-H_ax), 2.16 (m, 2H, 5,6-H_eq), 2.28

(dd, 1H, J ) 11.7, 11.7, 6-H_ax), 2.46 (dd, 1H, J ) 8.6, 8.6, 2-H),

2.87 (m, 2H, benzylic CH₂), 3.58 (s, 2H, CH₂OH), 3.82 (s, 3H,

OCH₃), 6.66 (s, 1H, 6′-H), 6.93 (s, 1H, 3′-H). This hydroxy

ketone (45 mg, 0.090 mmol) was then methylenated in the

manner previously described for 8d , affording 7.0 mg (21%)

of the desired olefin as a colorless oil: ¹H NMR 1.09 and 0.95

(2s, 2 × 3H, geminal CH₃’s), 1.33 (m, 2H, 4-H), 1.85 (m, 1H,

5-H_ax), 1.97 (dd, 1H, J ) 12.9, 12.9, 6-H_ax), 2.09 (dd, 1H, J )

11.4, 3.7, 2-H_eq), 2.21 (dd, 1H, J ) 13.0, 4.1, 6-H_eq), 2.82 and

2.57 (d of AB q, 2H, J _AB) 13.5, J _A) 3.7, J _B) 11.4, benzylic

CH₂), 3.54 (s, 2H, CH₂OH), 3.80 (s, 3H, OCH₃), 4.29 (s, 1H,

methylidene H), 4.54 (s, 1H, Ar-OH), 4.62 (s, 1H, methylidene

H), 6.53 (s, 1H, 6′-H), 6.94 (s, 1H, 3′-H); ¹³C NMR 28.9, 33.4,

34.4, 37.0, 54.7, 57.2, 68.1, 108.2, 112.5, 115.1, 120.5, 129.3,

147.5, 148.1; IR (neat) 3367 (br s), 2930 (s), 2872 (m), 1499

(s), 1404 (s), 1206 (s); HRMS calcd for C₁₈H₂₅BrO₃m/z

368.0987, found m/z 368.0971.

10.0, J _B) 3.4, benzylic CH₂), 3.86 (s, 3H, OCH₃), 4.68 (s, 4-H),

6.69 (s, 1H, 6′-H), 7.18 (s, 1H, 3′-H); ¹³C NMR 13.9, 12.4, 15.9,

20.1, 20.9, 21.4, 22.8, 27.5, 30.9, 34.4, 47.0, 56.8, 108.6, 112.0,

114.3, 120.1, 128.2, 148.1, 149.0, 152.2, 169.7; IR (neat) 1732

(s).

3,5,5-Tr im eth yl-6-[(4-n itr op h en yl)m eth yl]cycloh ex-2-

en -1-on e (20a ). This compound was prepared from isophor-

one (2.065 g, 14.94 mmol) and p-nitrobenzyl bromide (4.06 g,

18.8 mmol, 1.25 equiv) in the manner previously described for

enone 7a , affording 1.891 g (46%), of the nitro enone as a pale

yellow oil: ¹H NMR 0.98 and 1.13 (2s, 2 × 3H, geminal CH₃’s),

1.92 (s, 3H, 3-CH₃), 2.17 and 2.31 (AB q, 2H, J _AB) 18.5, 4-H),

2.38 (dd, 1H, J ) 9.0, 3.3, 6-H), 2.75 and 3.05 (d of AB q, 2H,

J _AB) 14.0, J _A) 3.2, J _B) 8.9, benzylic CH₂), 5.84 (s, 1H, 2-H),

7.33 and 7.53 (AB q, 4H, J _AB) 8.2, Ar-H); ¹³C NMR 22.2, 23.6,

28.5, 30.6, 36.6, 45.3, 58.5, 122.9, 123.2, 124.4, 128.9, 129.5,

145.6, 149.8, 158.3, 199.6; IR (neat) 2963 (br, m), 1667 (s).

Anal. (C₁₆H₁₉NO₂) C, H, N.

3,5,5-Tr im eth yl-6-[(3-m eth yl-4-n itr op h en yl)m eth yl]-1-

m eth ylid en ecycloh ex-2-en e (21). This compound was pre-

pared from enone 20a (21 mg, 0.080 mmol) in the manner

previously described for olefin 8a , using 3 equiv of [(trimeth-

ylsilyl)methyl]lithium, and allowing 18 h for the subsequent

elimination step, affording 3.5 mg (16%) of the nitro diene as

a pale yellow oil: ¹H NMR 0.89 and 1.15 (2s, 2 × 3H, geminal

CH₃’s), 1.71 and 2.11 (AB q, 2H, J _AB) 18.1, 4-H), 1.78 (s, 3H,

3-CH₃), 1.97 (dd, 1H, J ) 11.3, 2.7) and 2.91 (dd, 1H, J ) 12.8,

2.9) [benzylic CH₂], 2.58 (s, 3H, Ar-CH₃), 3.96 and 4.55 (2s, 2

× 1H, methylidene CH₂), 5.82 (s, 1H, 2-H), 6.98 (s, 1H, 2′-H),

6.99 (d, 1H, J ) 7.6, 6′-H), 7.88 (d, 1H, J ) 8.5, 5′-H); ¹³C NMR

21.0, 23.8, 27.9, 28.4, 33.4, 35.5, 41.6, 53.8, 112.0, 122.8, 124.6,

128.2, 133.5, 134.0, 136.1, 144.1, 147.1, 148.4; IR (neat) 2928

(w, br), 1518 (s), 1342 (s). Anal. (C₁₈H₂₃NO₂) C, H, N.

3,5,5-Tr im e t h yl-1-m e t h ylid e n e -6-[(4-n it r op h e n yl)-

m eth yl]cycloh ex-2-en e (22a ). To a flame-dried 10 mL rb

flask containing enone 20a (114 mg, 0.417 mmol) in 2.0 mL of

THF at 0 °C was added Tebbe’s reagent [(µ-chloro-µ-methyl-

ene)[bis(cyclopentadienyl)titanium]dimethylaluminum] (1.7 mL

of a 0.50 M solution in toluene, 0.84 mmol, 2.0 equiv) dropwise

over a period of 5 min. The reaction mixture was then allowed

to warm to rt and stirred 45 min before cooling to 0 °C and

the addition of 0.5 mL of 1 N NaOH. The reaction mixture

was then diluted with hexanes (50 mL) and filtered through

a pad of Celite and silica gel. The organic solution was dried

(Na₂SO₄) and concentrated under reduced pressure. Purifica-

tion by flash column chromatography (silica gel, hexanes/

EtOAc, 95:5) afforded 16.1 mg (14%) of the desired diene as a

colorless oil: ¹H NMR 0.89 and 1.13 (2s, 2 × 3H, geminal

CH₃’s), 1.71 and 2.11 (AB q, 2H, J _AB) 18.1, 4-H), 1.78 (s, 3H,

3-CH₃), 1.96 (dd, 1H, J ) 11.4, 3.1) and 2.98 (dd, 1H, J ) 12.7,

3.3) [benzylic CH₂], 2.30 (dd, 1H, J ) 12.5, 11.6, 6-H), 3.91

and 4.53 (2s, 2 × 1H, methylidene CH₂), 5.81 (s, 1H, 2-H), 7.17

(d, 2H, J ) 8.6, 2′,6′-H), 8.08 (d, 2H, J ) 8.6, 3′,5′-H); ¹³C NMR

23.6, 27.7, 28.2, 33.2, 35.5, 41.3, 53.7, 111.8, 122.4, 123.0 (2C),

130.3 (2C), 135.9, 143.7, 146.1, 149.9; IR (neat) 2930 (br, w),

1518 (s), 1344 (s). Anal. (C₁₇H₂₁NO₂) C, H, N.

8-[(2-Acetoxy-4-br om o-5-m eth oxyp h en yl)m eth yl]-5,7,7-

tr im eth ylsp ir o[2.5]oct-4-en e (13). To a flame-dried 10 mL

rb flask containing 20 mg (0.05 mmol) of diene 12 in 1 mL of

1,2-dichloroethane at 0 °C was added diethylzinc (250 µL of a

1.0 M solution in hexanes, 0.26 mmol, 5.0 equiv). Chlor-

oiodomethane (37 µL, 0.50 mmol, 10.0 equiv) was added

dropwise, and the mixture was allowed to warm to rt. After

9 h, the reaction mixture was quenched at 0 °C with 10 mL of

saturated NH₄Cl, and the reaction mixture was extracted with

EtOAc (50 mL). The organic phase was washed with brine

(20 mL), dried (Na₂SO₄), and concentrated under reduced

pressure. Purification by flash column chromatography (silica

gel, hexanes/EtOAc, gradient) afforded 20 mg (96%) of the

spirocyclopropane as a colorless syrup: ¹H NMR -0.07 (ddd,

1H, J ) 11.0, 9.3, 5.9, cyclopropyl H), 0.16 (ddd, 1H, J ) 11.5,

9.4, 6.1, cyclopropyl H), 0.32 (ddd, 1H, J ) 10.1, 5.8, 5.8,

cyclopropyl H), 0.43 (ddd, 1H, J ) 9.8, 6.1, 6.1, cyclopropyl

H), 1.03 and 1.06 (2s, 2 × 3H, geminal CH₃’s), 1.60 and 1.98

(AB q, 2H, J _AB) 17.8, 6-H), 1.69 (s, 3H, 5-CH₃), 2.25 (s, 3H,

1-H yd r oxy-4,6,6-t r im et h yl-2-m et h ylid en e-1-[(4-n it r o-

p h en yl)m eth yl]cycloh ex-3-en e (23). To a flame-dried 10

mL rb flask containing 31 mg (0.12 mmol) of diene 22a in 1.6

mL of CH₂Cl₂at rt was added selenium(IV) oxide (SeO₂) (6.4

mg, 0.060 mmol, 0.50 equiv), followed by (tert-butyl)hydro-

peroxide (76 µL of a 3.0 M solution in 2,2,4-trimethylpentane,

0.23 mmol, 2.0 equiv), and the reaction mixture was allowed

to stir at rt for 42 h. The solvent was then removed under

reduced pressure, and the residue was purified by flash column

chromatography (silica gel, hexanes/EtOAc, 15:1), affording 4.2

mg (13%) of the desired tertiary alcohol as a pale yellow oil:

¹H NMR 0.89 and 1.17 (2s, 2 × 3H, geminal CH₃’s), 1.81 (s,

3H, 3-CH₃), 1.95 and 2.35 (AB q, 2H, J _AB) 18.3, 4-H), 2.69

and 3.02 (AB q, 2H, J _AB) 13.0, benzylic CH₂), 4.23 and 4.61

(2s, 2 × 1H, methylidene CH₂), 5.88 (s, 1H, 2-H), 7.22 (d, 2H,

J ) 9.6, 2′,6′-H), 8.05 (d, 2H, J ) 9.6, 3′,5′-H); ¹³C NMR 23.2

(2C), 29.7, 38.0, 39.5, 45.6, 78.4, 110.3, 122.3, 124.1, 131.9,

135.8, 146.2, 146.5, 146.6; IR (neat) 3577 (br, m), 2966 (m),

1518 (s), 1344 (s). Anal. (C₁₇H₂₁NO₃) C, H, N.

acetate CH₃), 2.39 and 2.65 (d of AB q, 2H, J _AB) 13.6, J _A

)

Novel Nonsterodial Progesterone Receptor Antagonists

J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9 1787

3,5,5-Tr im eth yl-1-m eth ylid en e-6-[(4-n itr op h en yl)th io]-

cycloh ex-2-en e (22b). To a flame-dried 100 mL rb flask

containing diisopropylamine (338 µL, 2.41 mmol, 1.10 equiv)

in 10 mL of THF at -72 °C was added n-BuLi (1.00 mL of a

2.41 M solution in hexanes, 2.41 mmol, 1.10 equiv). After 20

min at -78 °C, isophorone (329 µL, 2.19 mmol) was added

dropwise as a solution in 2 mL of THF, and the reaction

mixture was allowed to gradually warm to 0 °C over 90 min

before the addition of 4-nitrophenyl disulfide (1.19 g, 3.29

mmol, 1.50 equiv) as a solution in 5 mL of THF. The resultant

dark-orange reaction solution was allowed to warm to rt and

stirred for 15 h before cooling to 0 °C, and the reaction was

quenched with 10 mL saturated NH₄Cl. The reaction mixture

was then extracted with 60 mL of EtOAc, and the organic

phase was washed with brine (40 mL), dried (Na₂SO₄), and

concentrated under reduced pressure. Purification by flash

column chromatography (silica gel, hexanes/EtOAc, 6:1) af-

forded 462 mg (72%) of the thiophenyl-substituted enone as

an orange oil (R_f0.52, 2:1 hexanes/EtOAc). This intermediate

enone was then carried on to the next step without further

purification. To a flame-dried 10 mL rb flask containing the

thiophenyl-substituted isophorone (25 mg, 0.090 mmol) in 0.5

mL of THF at 0 °C was added Tebbe’s reagent (350 µL of a

0.50 M solution in toluene, 0.17 mmol, 2.00 equiv) dropwise

over a period of 5 min. The reaction mixture was then allowed

to warm to rt and stirred 4 h before cooling to 0 °C and the

addition of 0.5 mL of methanol. The reaction mixture was then

diluted with 4:1 hexanes/EtOAc (50 mL) and filtered through

a pad of Celite and silica gel. The organic solution was dried

(Na₂SO₄) and concentrated under reduced pressure. Purifica-

tion by flash column chromatography (basic alumina, Brock-

man, hexanes/EtOAc, 10:1) afforded 2.8 mg (11%) of the

desired diene as a colorless oil (R_f0.67, 2:1 hexanes/EtOAc):

¹H NMR 1.04 and 1.15 (2s, 2 × 3H, geminal CH₃’s), 1.79 (s,

3H, 3-CH₃), 1.84 and 2.23 (AB q, 2H, J _AB) 17.4, 4-H), 3.63 (s,

1H, 6-H), 4.62 and 4.74 (2s, 2 × 1H, methylidene CH₂), 5.87

(s, 1H, 2-H), 7.46 (d, 2H, J ) 9.6, 2′,6′-H), 8.11 (d, 2H, J ) 9.6,

3′,5′-H); HRMS calcd for C₁₆H₁₉NO₂S m/z 289.1137, found m/z

289.1152.

(3R )-2′-[(t er t -Bu t yld im e t h ylsilyl)oxy]cyclocym op ol

Mon om eth yl Eth er (25a ). To a flame-dried 100 mL rb flask

containing 1 (1.38 g, 3.30 mmol) in 10 mL of anhydrous CH₂Cl₂

at rt were added tert-butylchlorodimethylsilane (0.62 g, 4.1

mmol, 1.3 equiv), imidazole (0.57 g, 8.3 mmol, 2.5 equiv), and

DMAP (50 mg, 0.4 mmol, 0.1 equiv), and the mixture was

stirred at rt for 6 h. The reaction mixture was then diluted

with 50 mL of CH₂Cl₂and successively washed with 1.0 M

NaHSO₄(30 mL) and brine (30 mL). The organic solution was

then dried (Na₂SO₄) and concentrated under reduced pressure.

Purification by flash column chromatography (silica gel, hex-

anes/EtOAc, gradient elution) afforded 1.72 g (98%) of the

silylated phenol as a white solid: ¹H NMR 0.22 and 0.23 [2s,

2 × 3H, Si(CH₃)₂], 1.01 [s, 9H, SiC(CH₃)₃], 1.08 and 1.18 (2s,

2 × 3H, geminal CH₃’s), 2.02-2.33 (m, 4H, 5,6-H), 2.58 (s, 1H,

3-H), 2.60 (dd, 1H, J ) 20.1, 11.9) and 2.88 (d, 1H, J ) 20.1,

11.4) [benzylic CH₂], 3.80 (s, 3H, OCH₃), 4.30 and 4.59 (2s, 2

× 1H, methylidene CH₂), 4.44 (dd, 1H, J ) 11.1, 4.2, 1-H),

6.55 (s, 1H, 6′-H), 6.92 (s, 1H, 3′-H); ¹³C NMR -4.1, -4.0, 18.3,

24.2, 25.9, 27.2, 28.0, 32.0, 34.7, 39.9, 53.8, 56.8, 63.5, 108.1,

112.4, 114.4, 123.0, 131.1, 144.9, 147.7, 149.9.

0.22 [2s, 2 × 3H, Si(CH₃)₂], 0.96 and 0.98 (2s, 2 × 3H, geminal

CH₃’s), 1.03 [s, 9H, SiC(CH₃)₃], 1.23-1.32 (m, 2H, 5-H), 1.53-

1.60 (m, 2H, 4-H), 1.98 (ddd, 1H, J ) 12.9, 8.7, 4.3, 6-H_ax),

2.14-2.20 (m, 1H, 6-H_eq), 2.24 (dd, 1H, J ) 10.9, 3.8, 2-H),

2.65 and 2.78 (d of AB q, 2H, J _AB) 13.9, J _A) 3.4, J _B) 11.5,

benzylic CH₂), 3.80 (s, 3H, OCH₃), 4.30 and 4.58 (2s, 2 × 1H,

methylidene CH₂), 6.61 (s, 1H, 6′-H), 6.92 (s, 1H, 3′-H).

(3R)-1-Debr om ocyclocym opol Mon om eth yl Eth er (27a).

To a 10-mL rb flask containing 26a (16 mg, 0.036 mmol) at 0

°C in 2 mL of THF was added TBAF (200 µL of a 1.00 M

solution in THF, 0.2 mmol, 6 equiv). After 10 min at 0 °C, pH

7 potassium phosphate buffer was added, and the reaction

mixture was extracted with hexanes. The resultant organic

solution was dried (Na₂SO₄) and concentrated under reduced

pressure. Purification by flash column chromatography (silica

gel, 10% EtOAc in hexanes) afforded 7.5 mg (61%) of the

debromophenol as a colorless oil. The H NMR spectrum and

TLC elution properties of this compound were identical to

those reported for the racemic compound (8a ): [R]²⁴+16.4°

(1.00, CHCl₃). Anal. (C₁₇H₂₃BrO₂) C, H.

(3S )-2′-[(t er t -Bu t yld im e t h ylsilyl)oxy]cyclocym op ol

Mon om eth yl Eth er (25b). This silylated natural product

was prepared from 2 (0.41 g, 0.99 mmol) in the manner

previously described for 25a , affording 0.52 g (98%) of the

desired silyl ether as a colorless syrup: ¹H NMR 0.20 and 0.24

[2s, 2 × 3H, Si(CH₃)₂], 0.98 and 1.24 (2s, 2 × 3H, geminal

CH₃’s), 1.02 [s, 9H, SiC(CH₃)₃], 2.03-2.10 (m, 2H, 6-H), 2.27-

2.37 (m, 3H, 3,5-H), 2.78 and 2.95 (d of AB q, 2H, J _AB) 15.7,

J _A) 3.1, J _B) 11.0, benzylic CH₂), 3.79 (s, 3H, OCH₃), 4.23

(dd, 1H, J ) 11.0, 4.2, 1-H), 4.61 and 4.81 (2s, 2 × 1H,

methylidene CH₂), 6.62 (s, 1H, 6′-H), 6.93 (s, 1H, 3′-H).

(3S)-1-Debr om ocyclocym opol Mon om eth yl Eth er (27b).

This compound was prepared from 25b (0.40 g, 0.75 mmol) in

two steps in the manner previously described for the 27a ,

affording 140 mg (55%) of the debromophenol as a colorless

oil. The H NMR spectrum and TLC elution properties of this

compound were identical to those reported for the racemic

compound (8a ).

Cotr a n sfection Assa ys. Cotransfection assays using hPR-

B1,^7a,bhAR,^7chGR,^7dhER,^7fand hMR^7ewere performed in CV-1

cells as described in the literature.⁸CV-1 cells (African green

monkey kidney fibroblasts) were cultured in the presence of

Dulbecco’s Modified Eagle Medium (DMEM) supplemented

with 10% charcoal resin-stripped fetal bovine serum and then

transferred to 96-well microtiter plates one day prior to

transfection. pRShPR-B1 is a pBR322 plasmid containing

hPR-B (from D. McDonnell and B. O’Malley, Baylor College

of Medicine) with the Tau-1 region of hGR inserted into the

N-terminal region as a BglII fragment at the unique HincII

site of hPR using BglII linkers. This results in 175 amino acids

of hGR being inserted after amino acid residue 456 of hPR-B.

In addition, two amino acid residues specified by the linker

were included at either side of the Tau-1 domain. The GR

Tau-1 domain was added to hPR in order to enhance the

trancriptional gain of the receptor, giving better signal-to-noise

in the cotransfection assay. The modified receptor is termed

hPR-B1. The insertion is in the region of hPR N-terminal to

the DNA binding domain and leaves the ligand binding domain

unchanged. Cells were transiently transfected by the calcium

phosphate coprecipitation procedure with the following plas-

mids: pRShPR-B1, MMTV-LUC reporter, pRS-â-Gal and filler

DNA (pGEM). The receptor plasmid, pRShPR-B1, contained

the hPR-B1 under constitutive control of the SV-40 promoter.

The reporter plasmid, MMTV-LUC, contained the cDNA for

firefly luciferase (LUC) under control of the mouse mammary

tumor virus (MMTV) long terminal repeat, a conditional

promoter containing a progesterone response element. pRS-

â-Gal, coding for constitutive expression of E. coli â-galactosi-

dase (â-Gal), was included as an internal control for evaluation

of transfection efficiency and compound toxicity. After trans-

fection, media were removed and the cells were washed with

phosphate-buffered saline (PBS). Media-containing reference

compounds (i.e., progesterone and RU486) or test compounds

in concentrations ranging from 10^-12to 10^-5M were added to

the cells. Three to four replicates were used for each sample.

After incubation, the cells were washed with PBS, lysed with

Gen er a l P r oced u r e for Selective Alip h a tic Debr om i-

n a tion of Na tu r a l Cyclocym op ols 1 a n d 2. (2R)-2-[[4-

Br om o-2-[(ter t-bu tyldim eth ylsilyl)oxy]-5-m eth oxyph en yl]-

m et h yl]-3,3-d im et h yl-1-m et h ylid en ecycloh exa n e (26a ).

To a flame-dried 100 mL rb flask containing 25a (1.00 g, 1.88

mmol) in 50 mL of anhydrous benzene with 10 mg of AIBN at

rt was added n-Bu₃SnH (2.02 mL, 7.51 mmol, 4.00 equiv). After

18 h, TLC analysis indicated complete consumption of starting

material and formation of a slightly less polar product. Carbon

tetrachloride (10 mL) was added, and after 3 h at rt the

mixture was diluted to 200 mL with CH₂Cl₂and washed with

brine (100 mL). The resultant organic solution was dried

(Na₂SO₄) and concentrated under reduced pressure. Purifica-

tion by flash column chromatography (silica gel, 10% EtOAc

in hexanes) afforded 0.748 g (88%) of the debrominated

compound as a colorless, low-melting solid: ¹H NMR 0.21 and

1788 J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9

Triton X-100 buffer, and assayed for LUC and â-Gal

Hamann et al.

control) represents alkaline phosphatase expression as a

function of 1 nM progesterone alone.

activities using a luminometer or spectrophotometer, respec-

tively. Data evaluation was performed using the Oracle

relational database management system with analysis reports

and programs designed at Ligand. For each replicate, the

normalized response (NR) was calculated as LUC response/

â-Gal rate where â-Gal rate ) â-Gal × 1 × 10^-5/â-Gal

incubation time. The mean and standard error of the mean

(SEM) of the NR were calculated. Data were plotted as the

response of the compound compared to the reference com-

pounds over the range of the concentration-response curve.

For agonist experiments, the effective concentration that

produced 50% of the maximum response (EC₅₀) was quantified.

Agonist efficacy (%) was a function of LUC expression relative

to the maximum LUC production by the reference agonist,

progesterone. Antagonist activity was determined by testing

the amount of LUC expression in the presence of progesterone

at its EC₅₀concentration. The concentration of test compound

that inhibited 50% of LUC expression induced by progesterone

was quantified (IC₅₀). In addition, efficacy of antagonists was

determined as a function (%) of maximal inhibition. Cotrans-

fection studies with hAR, hGR, and hMR with the MMTV-

LUC reporter and hER with the MMTV-ERE5-LUC reporter

were carried out as described above to determine cross-

reactivity of test compounds.

Recep tor Bin d in g Assa ys. Binding assays using bacu-

lovirus-expressed hPR-A, hAR, hER, hMR, and hGR obtained

from CV-1 cell extract were performed as described in the

literature.^8,26Binding assays with hER were performed using

overexpressed receptor extracted from yeast. The receptor

protein is intact structurally as indicated by Western blot

analysis and is present as a single species. Binding of

receptor-containing extracts (total protein of 10 µg per well)

to tritiated ligand (5 nM) equilibrated at 4 °C for 16 h in the

presence of increasing amounts of unlabeled test compounds

(1 pM to 10 µM). Binding buffer contained 0.3 M KCl, 10 mM

Tris, pH 7.5, and 5 mM DTT. Nonspecific binding was

determined by incubating receptor extract and tritiated ligand

in the absence or presence of a 200-fold molar excess of

unlabeled estradiol. At the end of the incubation period, bound

and free ligand were separated by hydroxylapatite, and the

resultant ligand-receptor complex bound to hydroxylapatite

was washed with ice-cold buffer containing 0.3 M KCl, 10 mM

Tris, pH 7.5, three times; bound radioactivity was determined

using a scintillation counter. After correcting for nonspecific

binding, IC₅₀values were determined. The IC₅₀value is

defined as the concentration of competing ligand required to

decrease specific binding by 50%. The IC₅₀value was deter-

mined graphically from a log-logit plot of the data. K_ivalues

were determined by application of the Cheng-Prusoff equation

[K_i) IC₅₀/(1 + [L]/K_d)] to the IC₅₀values, where [L] is the

concentration of labeled ligand and K_dis the dissociation

constant of the labeled ligand.

T-47D Alk a lin e P h osp h a ta se Assa y. T-47D alkaline

phosphatase assays were performed as described in the

literature.^8,27The T-47D human breast-carcinoma cell line

(obtained from the American Type Culture Collection) was

grown in the presence of RPMI 1640 media (BioWhittaker)

with 10% (v/v) fetal bovine serum (Hyclone), 2.5 mM ^L-

glutamine, 60 µg/mL gentamycin, and 0.2 µg/mL insulin.

Three days before experiments, cells were transferred from

10 cm dishes to 96 well plates (1 × 10⁴cells/well). At the

beginning of each experiment, the media were removed and

replaced with fresh media [2% (v/v) charcoal resin-stripped

fetal bovine serum] containing either test compound or test

compound plus progesterone (1 × 10^-9M) and returned to a

37 °C incubator (5% CO₂). After 18-20 h, media were

aspirated and the cells were fixed for 30 min with 100 µL of

5% formalin (in PBS). The fixed cells were then washed and

75 µL of assay buffer (1 mg/mL p-nitrophenol phosphate in 1

M diethanolamine pH 9, 2 mM MgCl₂was added. Following

incubation at 19 °C for 70 min, the reaction was terminated

with the addition of 100 µL of 1 M NaOH. The absorbance at

405 nm was measured (Biomek). T-47D cells were prepared

as described above. Cells were incubated in the presence of 1

nM progesterone and test compound. The ordinate (% of

Mu r in e Uter in e Decid u a liza tion Assa y. Mature virgin

BALB/c (22 g mean weight) or ICR (30 g mean weight) mice

were housed in a light- (14 h light, 10 h darkness; lights off at

20.00 h) and temperature- (22 °C) controlled room and fed and

watered ad libitum. Females were caged with vasectomized

males of the same strain between 17.00 and 10.00 h, and

pseudopregnancy was dated from the morning when a vaginal

plug was detected (day 1). Mating was presumed to have

taken place at 02.00 (time 0).⁴¹Pseudopregnant mice were

treated intraluminally with either standard compounds (RU486)

or test compounds (27a , 37, and 22a ) at the specified times

post coitum. Control animals received an equivalent volume

of sesame oil. RU486 was first dissolved in 100% ethanol and

then diluted with sesame oil. Test compounds were dissolved

in sesame oil and kept at rt. On day 4 (16.00 h), 10 µL of

sesame oil was injected intraluminally into the right uterine

horn (stimulated), and the left horn was left undisturbed to

serve as an internal control (nonstimulated). At necropsy 72

h after application of the decidual stimulus, the uterine horns

were removed, trimmed, blotted and weighed. Decidual

response to trauma at the injection site was easily distin-

guished from the response to oil which stimulated deciduomata

along the length of the uterus. Uterine wet weight gain was

calculated by subtracting the weight of the nonstimulated horn

from that of the stimulated horn. Animals were treated

following the protocols: doses of RU486 ranging from 0.01 to

5.0 mg; doses of 27a , 37, and 22a ranging from 1.0 to 5.0 mg;

and sesame oil (0.1-0.2 mL) control, all given intraluminally

between day 3 and day 5 of pseudopregnancy.

Ack n ow led gm en t. We thank Professor William

Fenical of The Scripps Institution of Oceanography and

Dr. Charles Pathirana and Mr. Ted Ianiro for collection

and isolation of material for semisynthetic analogue

preparation and Dr. Keith Marschke for assistance with

data preparation.

Su p p or tin g In for m a tion Ava ila ble: Synthetic proce-

dures and chemical characterization data for compounds 5,

8c,d , 12, 16, 18, 19, 24, 28b, 30, 31, 34a ,b, and 35-37 (16

pages). Ordering information is given on any current mast-

head page.

Refer en ces

(1) (a) Murphy, A. A.; Kettel, L. M.; Morales, A. J .; Roberts, V. J .;

Yen, S. S. Regresssion of Uterine Leiomyomata in Response to

the Antiprogesterone RU486. J . Clin. Endocrinol. Metab. 1993,

76, 513-517. (b) Bakker, G. H.; Setyono-Han, B.; Portengen, H.;

De J ong, F. H.; Foekens, J . A.; Klijn, J . G. Treatment of Breast

Cancer with Antiprogestins: Preclinical and Clinical Studies.

J . Steroid Biochem. Mol. Biol. 1990, 37, 789-794. (c) Kettel, L.

M.; Murphy, A. A.; Mortola, J . F.; Liu, J . H.; Ulmann, A.; Yen,

S. S. Endocrine Responses to Long-term Administration of

Antiprogesterone RU486 in Patients with Pelvic Endometriosis.

Fertil. Steril. 1991, 56, 402-407. (d) Lamberts, S. W.; Tanghe,

H. L.; Averaat, C. J .; Braakman, R.; Wijngaarde, R.; Koper, J .

W.; J ong, W. Mifepristone (RU486) Treatment of Meningiomas.

J . Neurol. Neurosurg. Psychiatry 1992, 55, 486-490. (e) Batista,

M. C.; Bristow, T. L.; Mathews, J .; Stokes, W. S.; Loriaux, D.

L.; Nieman, L. K. Daily Administration of the Progesterone

Antagonist RU 486 Prevents Implantation in the Cycling Guinea

Pig. Am. J . Obstet. Gynecol. 1991, 165, 82-86.

(2) (a) Evans, R. M. The Steroid and Thyroid Hormone Receptor

Superfamily. Science 1988, 240, 889-895. (b) Stein, R. B. In New

Drugs From Natural Sources; Coombes, I., J ames, D., Eds.; IBC

Technical Services: Oxford, 1992; p 13. (c) Berger, T. S.;

Parandoosh, Z.; Perry, B. W.; Stein, R. B. Interaction of Gluco-

corticoid Analogues with the Human Glucocorticoid Receptor.

J . Steroid Biochem. Mol. Biol. 1992, 41, 733-738.

(3) (a) Teutsch, G.; Philibert, D. History and Perspectives of

Antiprogestins from the Chemist’s Point of View. Human

Reproduction 1994, 9 (Suppl. 1), 12-31. (b) A structurally

unrelated class of non-steroidal PR modulators has recently been

reported in the patent literature: Combs, D. W. 1-Arylsulphonyl,

Arylcarbonyl and 1-Arylphosphonyl-3-phenyl-1,4,5,6-tetrahy-

dropyridazines. US Patent no. WO 94/01412.

(4) McConnell, O. J .; Hughes, P. A.; Targett, N. M. Diastereomers

of Cyclocymopol Monomethyl Ether from Cymopolia barbata.

Phytochemistry 1982, 21, 2139-2141.

Novel Nonsterodial Progesterone Receptor Antagonists

J ournal of Medicinal Chemistry, 1996, Vol. 39, No. 9 1789

(5) A brief preliminary account of this work has been published:

Hamann, L. G.; Farmer, L. J .; J ohnson, M. G.; Goldman, M. E.;

Mais, D. E.; Davtian, A.; Bender, S. L.; J ones, T. K. Synthesis

and Biological Activity of Novel Non-Steroidal Progesterone

Receptor Antagonists. Ann. N. Y. Acad. Sci. 1995, 761, 383-

387.

(21) Umbreit, M. A.; Sharpless, K. B. Allylic Oxidation of Olefins by

Catalytic and Stoichiometric Selenium Dioxide with tert-Butyl

Hydroperoxide. J . Am. Chem. Soc. 1977, 99, 5526-5528.

(22) (a) Dess, D. B.; Martin, J . C. Readily Accessible 12-I-5 Oxidant

for the Conversion of Primary and Secondary Alcohols to

Aldehydes and Ketones. J . Org. Chem. 1983, 48, 4155-4156.

(b) Ireland, R. E.; Liu, L. An Improved Procedure for the

Preparation of the Dess-Martin Periodinane. J . Org. Chem. 1993,

58, 2899.

(6) (a) Gaillard, R. C.; Poffet, D.; Riondel, A. M.; Sauret, J .-H. RU486

Inhibits Peripheral Effects of Glucocorticoids in Humans. J . Clin.

Endocrinol. Metab. 1985, 61, 1009-1011. (b) Spitz, I. M.; Bardin,

C. W. Mifepristone (RU486)sA Modulator of Progestin and

Glucocorticoid Action. N. Engl. J . Med. 1993, 329, 404-412. (c)

Teutsch, G.; Gaillard-Moguilewsky, M.; Lemoine, G.; Nique, F.;

Philibert, D. Design of Ligands for the Glucocorticoid and

Progestin Receptors. Biochem. Soc. Trans. 1991, 19, 901-908.

(7) (a) Hollenberg, S. M.; Evans, R. M. Multiple and Cooperative

Trans-Activation Domains of the Human Glucocorticoid Recep-

tor. Cell 1988, 55, 899-906. (b) Vegeto, E.; Allan, G. F.; Schrader,

W. T.; Tsai, M. J .; McDonnell, D. P.; O’Malley, B. W. The

Mechanism of RU486 Antagonism is Dependent on the Confor-

mation of the Carboxy-Terminal Tail of the Human Progesterone

Receptor. Cell 1992, 69, 703-713. (c) Simental, J . A.; Sar, M.;

Lane, M. V.; French, F. S.; Wilson, E. M. Transcriptional

Activation and Nuclear Targeting Signals of the Human An-

drogen Receptor. J . Biol. Chem. 1991, 266, 510-518. (d) Giguere,

V.; Hollenberg, S. M.; Rosenfeld, M. G.; Evans, R. M. Functional

Domains of the Human Glucocorticoid Receptor. Cell 1986, 46,

645-652. (e) Arriza, J . L.; Weinberger, C.; Cerelli, G.; Glaser,

T. M.; Handelin, B. L.; Housman, D. E.; Evans, R. M. Cloning

of Human Mineralocorticoid Receptor Complementary DNA:

Structural and Functional Kinship with Glucocorticoid Receptor.

Science 1987, 237, 268-275. (f) Tzukerman, M. T.; Esty, A.;

Santiso-Mere, D.; Danielian, P.; Parker, M. G.; Stein, R. B.; Pike,

J . W.; McDonnell, D. P. Human Estrogen Receptor Transacti-

vational Capacity is Determined by Both Cellular and Promoter

Context and Mediated by Two Functionally Distinct Intramo-

lecular Regions. Mol. Endocrinol. 1994, 8, 21-30.

(8) Pathirana, C.; Stein, R. B.; Berger, T. S.; Fenical, W.; Ianiro,

T.; Mais, D. E.; Torres, A.; Goldman, M. E. Nonsteroidal Human

Progesterone Receptor Modulators from the Marine Alga, Cy-

mopolia barbata. Mol. Pharmacol. 1995, 47, 630-635.

(9) Ho¨gberg, H.-E.; Thomson, R. H.; King, T. J . The Cymopols, a

Group of Prenylated Bromohydroquinones from the Green

Calcareous Alga Cymopolia barbata. J . Chem. Soc., Perkin

Trans. 1 1976, 1696-1701.

(10) Finn, C. A.; Martin, L. Endocrine Control of the Timing of

Endometrial Sensitivity to a Decidual Stimulus. Biol. Reprod.

1972, 7, 82-86.

(11) Tanaka, A.; Sato, M.; Yamashita, K. Synthesis of (()-Cyclocy-

mopol. Agric. Biol. Chem. 1990, 54, 121-123.

(23) Burgess, E. M.; Penton, H. R., J r.; Taylor, E. A. Thermal

Reactions of Alkyl N-Carbomethoxysulfate Esters. J . Org. Chem.

1973, 38, 26-31.

²-cyclo-

(24) Grieco, P. A.; Pogonowski, C. S. Synthesis of 5-Alkyl-∆

pentenones and 6-Alkyl-∆²-cyclohexenones. J . Chem. Soc., Chem.

Commun. 1975, 72-73.

(25) Oppolzer, W.; Petrzilka, M. An Enantioselective Total Synthesis

of Natural (+)-Luciduline. Helv. Chim. Acta 1978, 61, 2755-

2762.

(26) Christensen, K.; Estes, P.; Onate, S.; Beck, C.; DeMarzo, A.;

Altman, M.; Lieberman, B.; St. J ohn, J .; Nordeen, S.; Edwards,

D. Characterization and Functional Properties of the A and B

Forms of Human Progesterone Receptors Synthesized in

Baculovirus System. Mol. Endocrinol. 1991, 5, 1755-1770.

(27) Lorenzo, D. D.; Albertini, A.; Zava, D. Progestin Regulation of

Alkaline Phosphatase in the Human Breast Cancer Cell Line

T-47D. Cancer Res. 1991, 51, 4470-4475.

(28) (a) Wen, D. X.; Xu, Y.-F.; Mais, D. E.; Goldman, M. E.;

McDonnell, D. P. The A and B Isoforms of the Human Proges-

terone Receptor Operate Through Distinct Signaling Pathways

Within Target Cells. Mol. Cell. Biol. 1994, 14, 8356-8364. (b)

McDonnel, D. P. Unraveling the Human Progesterone Receptor

Signal Transduction Pathway. T. E. M. 1995, 6, 133-138.

(29) McCormack, J . T.; Greenwald, G. S. Progesterone and Oestra-

diol-17â Concentrations in the Peripheral Plasma During Preg-

nancy in the Mouse. J . Endocrinol. 1974, 62, 101-107.

(30) Finn, C. A. Endocrine Control of Endometrial Sensitivity During

the Induction of the Decidual Cell Reaction in the Mouse. J .

Endocrinol. 1966, 36, 239-248.

(31) Rider, V.; McRae, A.; Heap, R. B.; Feinstein, A. Passive Im-

munization Against Progesterone Inhibits Endometrial Sensi-

tization in Pseudopregnant Mice and has Antifertility Effects

in Pregnant Mice which are Reversible by Steroid Treatment.

J . Endocrinol. 1985, 104, 153-158.

(32) Roblero, L. S.; Croxatto, H. B. Effects of RU486 on Development

and Implantation of Rat Embryos. Mol. Reprod. Dev. 1991, 29,

342-346.

(12) Clavel, J .-M.; Guillamel, J .; Demerseman, P.; Royer, R. Recher-

ches sur le benzofuranne. LVI. Syntheses dans la serie de

l’Euparone par acetylation de benzofurannes acetyles et meth-

oxyles sur homocycle. J . Heterocycl. Chem. 1977, 14, 219-224.

(13) Wiley, G. A.; Hershkowitz, R. L.; Rein, B. M.; Chung, B. C.

Studies in Organophosphorous Chemistry. I. Conversion of

Alcohols and Phenols to Halides by Tertiary Phosphine Diha-

lides. J . Am. Chem. Soc. 1964, 86, 964-965.

(14) (a) Paterson, I. R-Alkylation and R-alkylidenation of Carbonyl

Compounds by O-Silylated Enolate Phenylthioalkylation. Tet-

rahedron 1988, 44, 4207-4219. (b) Paterson, I.; Fleming, I.

Lewis Acid-Promoted Phenylthioalkylation of O-Silylated Eno-

lates. Tetrahedron Lett. 1979, 20, 2179-2182.

(15) (a) Peterson, D. J . A Carbonyl Olefination Reaction Using Silyl-

Substituted Organometallic Compounds. J . Org. Chem. 1968,

33, 780-784. (b) Ager, D. J . The Peterson Reaction. Synthesis

1984, 384-398.

(16) J ohnson, C. R.; Tait, B. D. A Cerium(III) Modification of the

Peterson Reaction: Methylenation of Readily Enolizable Car-

bonyl Compounds. J . Org. Chem. 1987, 52, 281-283.

(17) House, H. O.; Chu, C.-Y.; Phillips, W. V.; Sayer, T. S. B.; Yau,

C.-C. Synthesis of ω-Bromo Ketones. J . Org. Chem. 1977, 42,

1709-1717.

(18) Krishnamurthy, S. Lithium Tris[(3-ethyl-3-pentyl)oxy]aluminum

Hydride. A New Remarkably Chemoselective Reagent for the

Reduction of Aldehydes in the Presence of Ketones. J . Org.

Chem. 1981, 46, 4628-4629.

(19) Denmark, S. E.; Edwards, J . P. A Comparison of (Chloromethyl)-

and (Iodomethyl)zinc Cyclopropanation Reagents. J . Org. Chem.

1991, 56, 6974-6981.

(20) (a) Tebbe, F. N.; Parshall, G. W.; Reddy, G. S. Olefin Homolo-

gation with Titanium Methylene Compounds. J . Am. Chem. Soc.

1978, 100, 3611-3613. (b) Pine, S. H.; Pettit, R. J .; Geib, G. D.;

Cruz, S. G.; Gallego, C. H.; Tijerina, T.; Pine, R. Carbonyl

Methylenation Using a Titanium-Aluminum (Tebbe) Complex.

J . Org. Chem. 1985, 50, 1212-1216.

(33) Ghosh, D.; De, P.; Sengupta, J . Effect of RU486 on the Endome-

trial Response to Deciduogenic Stimulus in Ovariectomized

Rhesus Monkeys Treated with Oestrogen and Progesterone.

Human Reprod. 1992, 7, 1048-1060.

(34) Burgess, K. M.; J enkin, G.; Ralph, M. M.; Thorburn, G. D. Effect

of the Antiprogestin RU486 on Uterine Sensitivity to Oxytocin

in Ewes in Late Pregnancy. J . Endocrinol. 1992, 134, 353-360.

(35) Vinijsanun, A.; Martin, L. Effects of Progesterone Antagonists

RU486 and ZK98,734 on Embryo Transport, Development and

Implantation in Laboratory Mice. Reprod. Fertil. Dev. 1990, 2,

713-727.

(36) For a more detailed discussion of allylic strain in alkylidecyclo-

hexanes, see: J ohnson, F. Allylic Strain in Six-Membered Rings.

Chem. Rev. 1968, 68, 375-413.

(37) Wall, M. E.; Wani, M. C.; Manikumar, G.; Taylor, H.; Hughes,

T. J .; Gaetano, K.; Gerwick, W. H.; McPhail, A. T.; McPhail, D.

R. Plant Antimutagenic Agents, 7. Structure and Antimutagenic

Properties of Cymobarbatol and 4-Isocymobarbatol, New Cy-

mopols from Green Alga (Cymopolia barbata). J . Nat. Prod.

1989, 52, 1092-1099.

(38) Bender, S. L.; Goldman, M. E. Unpublished results.

(39) Allan, R. D.; Curtis, D. R.; Headley, P. M.; J ohnson, G. A.; Lodge,

D.; Twitchen, B. The Synthesis and Activity of cis- and trans-

2-(Aminomethyl)cyclopropanecarboxylic Acid As Conformation-

ally Restricted Analogs of GABA. J . Neurochem. 1980, 34, 652-

656.

(40) Still, W. C.; Kahn, M.; Mitra, A. Rapid Chromatographic

Technique for Preparative Separations with Moderate Resolu-

tion. J . Org. Chem. 1978, 43, 2923-2925.

(41) Bronson, F. H.; Dagg, C. P.; Snell, G. B. Reproduction. In Biology

of the Laboratory Mouse, 2nd ed.; Green, E. L., Ed.; McGraw-

Hill: New York, 1966; pp 187-204.

J M950747D

Products guided by the article

Product name:[5-Bromo-2-((1R,3R)-3-bromo-2,2-dimethyl-6-methylene-cyclohexylmethyl)-4-methoxy-phenoxy]-tert-butyl-dimethyl-silane

Cas No:156170-20-6

R&D Labs maybe for 156170-20-6

NINGBO YINZHOU PRECISE COLOR CO.,LTD.

Contact:86-574-88139809 86-574-83033159

Address:Qiming Road,Yinzhou,Ningbo,China
Shanghai Massive Chemical Technology Co., Ltd.

website:http://www.massivechem.com/

Contact:+86 21 34943721

Address:Room 435, 4th floor, Building 9, No. 2568 Gudai Road,Minhang District, Shanghai,
Frapp's Chemical (NFTZ) Co.,Ltd

Contact:+86-576-86137892

Address:General Chamber of Commercial Building, 159 Wanchang Middle Road, Wenling, Zhejiang, China
Zhejiang Linhai Xinhua Chemicals Factory

Contact:0086-13661858911

Address:Xunqiao Development Zone, Linhai, Zhejiang, China
Tractus Company Limited

Contact:+852-8198 2399

Address:9E, Leapont Industrial Building, 18-28 Wo Liu Hang Road, Shatin, New Territories, Hong Kong

Relevant to this article

Hydroboration. 90. Synthesis of 2-isobutyl- and 2-Isopropylapopinenes. Rates and Stoichiometry of the Hydroboration of 2-Organylapopinenes with Borane-Methyl Sulfide and Borane-Tetrahydrofuran

Doi:10.1021/jo00087a016
(1994)
Palladium nanoparticles catalyzed Sonogashira reactions for the one-pot synthesis of symmetrical and unsymmetrical diarylacetylenes

Doi:10.1016/j.catcom.2013.12.029
(2014)
Development of ruthenium(ii) complexes as topical antibiotics against methicillin resistant Staphylococcus aureus

Doi:10.1039/c3dt52879k
(2014)
NDI and DAN DNA: Nucleic acid-directed assembly of NDI and DAN

Doi:10.1021/jo402704z
(2014)
Copper(I)-catalyzed aryl or vinyl addition to electron-deficient alkenes cascaded by cationic cyclization

Doi:10.1021/ol500033w
(2014)
Stereoselective total synthesis of (+)-boronolide, (+)-anamarine, 8-epi-spicegerolide

Doi:10.1016/j.tetlet.2013.12.061
(2014)

Article Doi

Synthesis and biological activity of novel nonsteroidal progesterone receptor antagonists based on cyclocymopol monomethyl ether

DOI: 10.1021/jm950747d

Source and publish data:

Authors:

Article abstract of DOI:10.1021/jm950747d

Full text of DOI:10.1021/jm950747d

Products guided by the article

R&D Labs maybe for 156170-20-6

Relevant to this article

Hot Product