Novel optically active chroman derivatives, their preparation and novel intermediates
US4645845A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1984 |
| Grant date | Feb 24, 1987 |
| Priority date | — |
| Expiry date | Mar 12, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D311/72
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Novel optically active chroman derivatives of the general formulae Ia and Ib ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen or alkyl and X is --OH, --O--CO-alkyl, --O-alkyl, --O-tosyl, --O-mesyl, --O-benzenesulfonyl, Cl, Br or I, are prepared by a process in which PA0 (a) the racemate of the formula I' ##STR2## is esterified in the side chain with a carboxylic acid and then acylated with an optically active carboxylic acid halide of the general formula III ##STR3## or with the corresponding carboxylic anhydride, to give a chroman derivative IV ##STR4## or (b) the racemate I' is esterified in the side chain with the carboxylic acid from which III is derived, and, if required, the resulting ester is acylated with a carboxylic acid halide to give IV' ##STR5## the resulting mixture IV or IV', which consists of two diastereomers, is resolved by fractional crystallization, the diastereomers are hydrolyzed to the alcohols Ia and Ib and, if desired, these are converted to the other compounds Ia and Ib in a conventional manner. Useful optically active chroman derivatives Ia and Ib and diastereomeric chromanyl esters IV and IV' are also claimed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.