Method of producing enantiomerically pure R-(+)-alpha-lipoic acid and S-(-) a
US4772727A · kind A · utility
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4Claims
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Key dates
| Filing date | Aug 7, 1987 |
| Grant date | Sep 20, 1988 |
| Priority date | — |
| Expiry date | Aug 7, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D339/04
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A multistage method for producing R-(+)-.alpha.-lipoic acid and S-(-)-.alpha.-lipoic acid (thioctic acid) by reacting a compound of formula II ##STR1## by means of enantioselective epoxidation to the epoxy alcohol of formula III, ##STR2## reduction to 1,3-diol-dihydroxynone-8-ene of formula IV, ##STR3## reaction with a substituted sulfonic acid chloride to 1,3-disulfoxynone-8-ene of formula V, ##STR4## oxidation with ruthenium tetroxide to 6,8-disulfoxyoctanoic acid of formula VI ##STR5## and subsequent reaction with sodium sulfide/sulfur.
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