Patent US4588820A successfully refreshed from Google Patents.
US4588820A
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Process for epimerization at C6 of 3,4,5,6-tetrahydro-2H-pyran-2-one
Assignee: Merck and Co Inc
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Filing: 1984-06-11
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Granted: 1986-05-13
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Expires: 2004-06-11
Abstract
Abstract An external bond at the 6-position of a 3,4,5,6-tetrahydro-2H-pyran-2-one, as found in the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, is readily epimerized by treating an amide of the corresponding hydroxy acid with a sulfonyl chloride reagent.
Inventors
- 👤 Gerald E. Stokker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:59
CPC Classifications
C; C07; C07D; C07D309/00; C07D309/16; C07D309/28; C07D309/30; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/18; C07F7/1804
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
188 words
A process for preparing a compound of structural formula: ##STR12## which comprises treating a compound of structural formula: ##STR13## with an organic-sulfonyl halide of structural formula: R.sup.5 SO.sub.2 X wherein: X is halo; Z is a carbinol protecting group; R 1 is (a) hydrogen, or (b) methyl; R 3 and R 4 are independently (a) hydrogen, (b) C 1-3 alkyl, or (c) phenyl-C 1-3 alkyl, wherein the phenyl is unsubstituted or substituted with (i) C 1-3 alkyl, (ii) C 1-3 alkoxy or (iii) halo; R 2 is (a) ##STR14## wherein Q is ##STR15## R 6 is H or OH; R is hydrogen or methyl, and a, b, c, and d represent optional double bonds; or (b) ##STR16## wherein R 7 is phenyl or benzyloxy in which the phenyl in each case can be substituted with one or more substituents selected from C 1-3 alkyl, and halo, and R 8 and R 9 are C 1-3 alkyl or halo and e represents an optional double bond; and R 5 is (a) C 1-3 alkyl; or (b) phenyl, either unsubstituted or substituted with one or two C 1-3 alkyl groups.
Claim 2
Dependent Claim
188 words
A process for preparing a compound of structural formula: ##STR12## which comprises treating a compound of structural formula: ##STR13## with an organic-sulfonyl halide of structural formula: R.sup.5 SO.sub.2 X wherein: X is halo; Z is a carbinol protecting group; R 1 is (a) hydrogen, or (b) methyl; R 3 and R 4 are independently (a) hydrogen, (b) C 1-3 alkyl, or (c) phenyl-C 1-3 alkyl, wherein the phenyl is unsubstituted or substituted with (i) C 1-3 alkyl, (ii) C 1-3 alkoxy or (iii) halo; R 2 is (a) ##STR14## wherein Q is ##STR15## R 6 is H or OH; R is hydrogen or methyl, and a, b, c, and d represent optional double bonds; or (b) ##STR16## wherein R 7 is phenyl or benzyloxy in which the phenyl in each case can be substituted with one or more substituents selected from C 1-3 alkyl, and halo, and R 8 and R 9 are C 1-3 alkyl or halo and e represents an optional double bond; and R 5 is (a) C 1-3 alkyl; or (b) phenyl, either unsubstituted or substituted with one or two C 1-3 alkyl groups.
Claim 3
Dependent Claim
56 words
The process of claim 1, wherein X is chloro; Z is trialkylsilyl or carboxyacyl; b and d are double bonds or all of a, b, c and d are single bonds; R 3 is hydrogen and R 4 is benzyl; R 7 is phenyl substituted with C 1-3 alkyl and fluoro and R 5 is methyl.
Claim 4
Dependent Claim
10 words
The process of claim 2 for the preparation of: ##STR17##
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-12 | 1989-11-11 | 1990-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-12 | 1993-11-11 | 1994-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-12 | 1997-11-11 | 1998-05-13 | $7700.00 | Window Closed / Lapsed |