Process for preparing intermediates useful in the synthesis of vitamin D compounds
US6284928A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 2000 |
| Grant date | Sep 4, 2001 |
| Priority date | — |
| Expiry date | Feb 10, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C45/63
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to an improved process for preparing [(3aR,4S,7aS)4-bromooctahydro-7a-methyl-1H-indene-1,5-dione]. (S)-(+)-2,3,7,7a-tetrahydro-7a-methyl-1H-indene-1,5(6H)-dione is reduced by reaction with diisobutylaluminum hydride and hexamethylphosphoric triaminde in the presence of a catalyst of the formula R--Cu, wherein R is ##STR1## and R.sup.1, R.sup.2 and R.sup.3 are each, independently, selected from the group consisting of C.sub.1-7 alkyl, phenyl, phenyl substituted by at least one C.sub.1-4 alkyl group, benzyl, or benzyl substituted by at at least one C.sub.1-4 alkyl group to form a reductate. The reductate is then treated with a bromine-containing electrophile to yield (3aR,4S,7aS)4-bromooctahydro-7a-methyl-1H-indene-1,5-dione.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.