Patent US4189431A successfully refreshed from Google Patents.
US4189431A
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Alkinyl terminating groups in biogenetic-like cyclizations to steroids
Assignee: Leland Stanford Junior University
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Filing: 1977-08-03
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Granted: 1980-02-19
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Expires: 1997-08-03
Abstract
Abstract Polyenine compounds are provided having the naturally occurring geometry and a group which in the presence of acid initiates a carbocation cyclization to a steroid or A-nor-steroid structure, particularly the pregnane parent structure. The compounds are formed for the most part by condensation of two units prepared from readily available small molecules and are joined to form a polyenine, usually having a substituted carbocyclic ring which upon contact with a Lewis acid catalyst (includes protonic) cyclizes directly to provide the 5-membered D ring as well as substitution at the C-20 position.
Inventors
- 👤 William S. Johnson
- 👤 Michael B. Gravestock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 03:19
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/02; C07D307/34; C07D307/38; C07C; C07C29/00; C07C29/36; C07C29/38; C07C29/40; C07C29/42; C07C35/00; C07C35/02; C07C35/06; C07C403/00; C07C403/02; C07C45/00; C07C45/41; C07C45/56; C07C45/567; C07C45/57; C07C45/59; C07C45/61; C07C45/65; C07C45/66; C07C45/67; C07C45/673; C07C49/00; C07C49/20; C07C49/587; C07C49/647; C07C57/00; C07C57/18; C07C67/00; C07C67/27; C07C67/30; C07C67/317; C07C67/32; C07C67/333; C07C67/343; C07C67/347; C07D317/00; C07D317/08; C07D317/10; C07D317/12; C07D317/14; C07D317/16; C07D339/00; C07D339/02; C07D339/06; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/0803; C07B; C07B2200/00; C07B2200/09; C07C2601/00; C07C2601/06; C07C2601/10; C07C2601/12; C07C2601/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
57 words
A method for preparing a cyclization product having a structure B ##STR55## from a substrate having the structure A ##STR56## the method comprising: contacting said substrate in a solvent with from about 1 to 50 equivalents of a Lewis acid per equivalent of said substrate at a temperature in the range of about -50 to 10° C.
Claim 2
Independent Claim
57 words
A method for preparing a cyclization product having a structure B ##STR55## from a substrate having the structure A ##STR56## the method comprising: contacting said substrate in a solvent with from about 1 to 50 equivalents of a Lewis acid per equivalent of said substrate at a temperature in the range of about -50 to 10° C.
Claim 3
Dependent Claim
39 words
A method according to claim 1, wherein R 1 is methyl and said Lewis acid is selected from the group consisting of trifluoroacetic acid, trichloroacetic acid, formic acid, stannic chloride, titanium tetrachloride, zinc chloride, zinc bromide, and boron trifluoride.
Claim 4
Independent Claim
180 words
A method for preparing a cyclization product having a structure B ##STR57## from a substrate having the structure A ##STR58## wherein: a is hydrogen or lower alkyl of from 1 to 2 carbon atoms; R 1 is hydrogen or saturated aliphatic hydrocarbon of from 1 to 3 carbon atoms and having from 0 to 1 oxy, halo or tri-(lower alkyl)silyl substituent; h is derived from a nucleophile selected from the group consisting of alkenes, carbocyclic aromatics, oxy, halo, nitroalkane of from 1 to 6 carbon atoms and, when the nucleophile is hydroxy is taken together with i to form oxo; when not taken together with h, i is taken together with j to form a double bond, and j, when not taken together with i, is hydrogen or when h and i are oxo and said nucleophile is nitroalkane, oximino; the method comprising: contacting said substrate in a solvent containing said nucleophile with from about 1 to 50 equivalent of a Lewis acid per equivalent of said substrate at a temperature in the range of about -50° to 10° C.
Claim 5
Independent Claim
180 words
A method for preparing a cyclization product having a structure B ##STR57## from a substrate having the structure A ##STR58## wherein: a is hydrogen or lower alkyl of from 1 to 2 carbon atoms; R 1 is hydrogen or saturated aliphatic hydrocarbon of from 1 to 3 carbon atoms and having from 0 to 1 oxy, halo or tri-(lower alkyl)silyl substituent; h is derived from a nucleophile selected from the group consisting of alkenes, carbocyclic aromatics, oxy, halo, nitroalkane of from 1 to 6 carbon atoms and, when the nucleophile is hydroxy is taken together with i to form oxo; when not taken together with h, i is taken together with j to form a double bond, and j, when not taken together with i, is hydrogen or when h and i are oxo and said nucleophile is nitroalkane, oximino; the method comprising: contacting said substrate in a solvent containing said nucleophile with from about 1 to 50 equivalent of a Lewis acid per equivalent of said substrate at a temperature in the range of about -50° to 10° C.
Claim 6
Dependent Claim
16 words
A method according to claim 3, wherein said acid medium is derived from a protic acid.
Claim 7
Dependent Claim
18 words
A method according to claim 4, wherein said protic acid is a carboxylic acid and is said nucleophile.
Claim 8
Dependent Claim
19 words
A method according to claim 5, wherein the acid of said acidic medium is a Lewis acid metal halide.
Claim 9
Independent Claim
192 words
A method for preparing a cyclization product having a structure B ##STR59## from a substrate having the structure A ##STR60## wherein: a is hydrogen or lower alkyl of from 1 to 2 carbon atoms; R 1 is hydrogen or saturated aliphatic hydrocarbon of from 1 to 3 carbon atoms and having 0 to 1 oxy, halo or tri-(lower alkyl) silyl substituent; e is lower alkyl of from 1 to 2 carbon atoms; h is derived from a nucleophile selected from the group consisting of alkenes, carbocyclic aromatics, oxy, halo, nitroalkane of from 1 to 6 carbon atoms, and, when the nucleophile is hydroxy is taken together with i to form oxo; when not taken together with h, i is taken together with j to form a double bond; and j when not taken together with i, is hydrogen or when h and i are oxo and said nucleophile is nitroalkane, oximino; the method comprising: contacting said substrate in an acidic halocarbon medium at a temperature in the range of about -50° to 10° C. with an acid at an equivalent ratio of 1-50:1 to said substrate in the presence of a nucleophile.
Claim 10
Independent Claim
192 words
A method for preparing a cyclization product having a structure B ##STR59## from a substrate having the structure A ##STR60## wherein: a is hydrogen or lower alkyl of from 1 to 2 carbon atoms; R 1 is hydrogen or saturated aliphatic hydrocarbon of from 1 to 3 carbon atoms and having 0 to 1 oxy, halo or tri-(lower alkyl) silyl substituent; e is lower alkyl of from 1 to 2 carbon atoms; h is derived from a nucleophile selected from the group consisting of alkenes, carbocyclic aromatics, oxy, halo, nitroalkane of from 1 to 6 carbon atoms, and, when the nucleophile is hydroxy is taken together with i to form oxo; when not taken together with h, i is taken together with j to form a double bond; and j when not taken together with i, is hydrogen or when h and i are oxo and said nucleophile is nitroalkane, oximino; the method comprising: contacting said substrate in an acidic halocarbon medium at a temperature in the range of about -50° to 10° C. with an acid at an equivalent ratio of 1-50:1 to said substrate in the presence of a nucleophile.
References Cited (Backward Citations)
US3884945A
Cited
US4032579A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |