Separating optically pure d-l-isomers of menthol, neomenthol and isomenthol
US3943181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1974 |
| Grant date | Mar 9, 1976 |
| Priority date | — |
| Expiry date | Sep 3, 1994 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C35/12
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the separation of optically active d- and l-isomers of a compound selected from the group consisting of menthol, neomenthol and isomenthol, which comprises esterifying a d,l-isomeric mixture of the compound with an acid selected from the group consisting of benzoic acid optionally carrying at least one substituent on the benzene ring and hexahydrobenzoic acid; forming a supersaturated solution or a supercooled melt of the d,l-ester; inoculating the solution or melt with crystals of the d- or l-form of the ester to effect selective crystllization of one of the two optical isomers; separating the crystals and subjecting them to hydrolysis to yield the corresponding enantiomorph of the starting compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.