Stereochemistry of the Dihydro Compound From Lithium/Ammonia Reduction of 3-Methoxy-7,8,9,10-tetrahydro-6H-dibenzo[b,d]pyran-6-one

Abstract

X-Ray crystallography has established that the lithium/ammonia reduction of 3-methoxy-7,8,9,10-tetrahydro-6H-dibenzo[ b,d ]pyran-6-one gives the cis-dihydro compound (6aRS,10aSR)-3-methoxy-6a,7,8,9,10,10a-hexahydro-6H-dibenzo[ b,d ]pyran-6-one (7).