Dj. Collins et al., STEREOCHEMISTRY OF THE DIHYDRO COMPOUND FROM LITHIUM AMMONIA REDUCTION OF XY-7,8,9,10-TETRAHYDRO-6H-DIBENZO[B,D]PYRAN-6-ONE/, Australian Journal of Chemistry, 49(6), 1996, pp. 719-721
X-Ray crystallography has established that the lithium/ammonia reducti
on of oxy-7,8,9,10-tetrahydro-6H-dibenzo[b,d]pyran-6-one gives the cis
-dihydro compound ,7,8,9,10,10a-hexahydro-6H-dibenzo[b,d]pyran-6-one (
7).