Stereoselective process for alkyl phenylglycolic acids
US6180823A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1998 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | Nov 6, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C59/54
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for preparing an alkyl phenylglycolic acid is disclosed. It follows the sequence of condensing a substituted acetaldehyde with mandelic acid to provide a 5-phenyl-1,3-dioxolan-4-one, which is condensed with an alkyl ketone or aldehyde to provide a 5-(1-hydroxyalkyl)-5-phenyl-1,3-dioxolan-4-one, which is dehydrated to a 5-(1-alkenyl)-5-phenyl-1,3-dioxolan-4-one. The 5-(1-alkenyl)-5-phenyl-1,3-dioxolan-4-one may be hydrolyzed and reduced to an .alpha.-alkylphenylglycolic acid or the hydrolysis and reduction steps may be reversed. The process enables the production of single enantiomers of cyclohexylphenylglycolic acid (CHPGA). An analogous process for racemic CHPGA is disclosed employing racemic mandelic acid and acetone. Novel intermediates in the process are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.