Method of controlling the epimeric distribution in the preparation of 16,17-acetals of pregnane derivatives
US4925933A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1987 |
| Grant date | May 15, 1990 |
| Priority date | — |
| Expiry date | Sep 11, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07J71/0031
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A method of controlling the epimeric distribution in the preparation of 16,17-acetals of pregnane derivatives characterized in reaction of a corresponding 16,17-acetonide with an aldehyde or ketone in (a) hydrocarbon solvent wherein the solubility of the pregnane derivative is less than 1 mg/l or in a halogenated hydrocarbon solvent together with a hydrohalogen acid or an organic sulphonic acid as catalyst and in the presence of small grains of an insert material in the reaction medium or (b) a halogenated hydrocarbon solvent together with a hydrohalogen acid an organic sulphonic acid as catalyst and in the presence of an epimeric distribution modifier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.