Claims
- 1. A process for the production of (6S)-(-) methyl-6,8-dihydroxyoctanoate, in which a lactone having the formula ##STR2## wherein X is a heteroatom substituent, is reacted with sodium methoxide.
- 2. A process for the production of (6R)-(+) methyl-6,8-dihydroxyoctanoate, in which a lactone having the formula ##STR3## wherein X is a heteroatom substituent, is reacted with sodium methoxide.
- 3. A process for the production of (.+-.) methyl-6,8-dihydroxyoctanoate, in which a lactone having the formula ##STR4## wherein X is a heteroatom substituent, is reacted with sodium methoxide.
- 4. A process for the preparation of a substantially single enantiomer of lipoic acid or a derivative thereof, having either (R) or (S) symmetry, comprising the steps of:
- oxidizing a 2-substituted cyclohexanone to obtain a substantially single enantiomer of a lactone of formula I having either (R) or (S) symmetry ##STR5## wherein X is a heteroatom substituent; and converting the lactone into the lipoic acid or derivative thereof, said process comprising the steps of:
- a) transesterifying the (R)-lactone of formula I with sodium methoxide to give a substantially (R) methyl ester;
- b) inverting the substantially (R) methyl ester via a Mitsunobu reaction;
- c) hydrolysis to afford a substantially (S) methyl ester; and
- d) converting the (S) methyl ester into the substantially single enantiomer of the (R) lipoic acid.
- 5. A process for the preparation of a substantially single enantiomer of lipoic acid or a derivative thereof, having either (R) or (S) symmetry, comprising the steps of:
- oxidizing a 2-substituted cyclohexanone to obtain a substantially single enantiomer of a lactone of formula I having either (R) or (S) symmetry ##STR6## wherein X is a heteroatom substituent; and converting the lactone into the lipoic acid or derivative thereof, said process comprising the steps of:
- a) transesterifing the (R) lactone of formula I with sodium methoxide to afford a substantially (R) methyl ester; and
- b) converting the (R) methyl ester into the substantially single enantiomer of (S) lipoic acid.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9510858 |
May 1995 |
GBX |
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Parent Case Info
This application is the national phase of international application PCT/GB96/01278, filed May 30, 1996 which designated the U.S.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
102e Date |
371c Date |
PCT/GB96/01278 |
5/30/1996 |
|
|
5/12/1999 |
5/12/1999 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO96/38437 |
12/5/1996 |
|
|
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
5489694 |
Paust et al. |
Feb 1996 |
|