Stereoselective preparation of hexahydro dibenzopyranones and intermediates therefor
US4176233A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 21, 1978 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Apr 21, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2602/42
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
An optically active 4-(4-substituted-2,6-dihydroxyphenyl)-6,6-dimethyl-2-norpinanone is reacted with a protonic acid to provide an optical isomer of a cis-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-dibe nzo[b,d]pyran-9-one. Reaction of said norpinanone with a Lewis acid provides an optical isomer of trans-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-di benzo[b,d]pyran-9-one. The optically active norpinanones are prepared by reaction of a 5-substituted-resorcinol with an optically active 6,6-dimethyl-2,4-diacetoxy-2-norpinene or an optically active 6,6-dimethyl-2,2-diacetoxy-3-norpinene, which compounds are derived from optically active .beta.-pinenes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.