Conversion of (+) -Limonen-10-ol to Bicyclo [3.3.0] octane Skeleton. Synthesis of a Key Intermediate for Carbacyclin

抄録

The conversion of (+) -limonen-10-ol (7) into the key intermediate for the synthesis of carbacyclin (1), (+) - (1S, 2R, 3R, 5R) -3-acetoxy-2-methoxycarbony1-7-oxobicyclo [3.3.0] octane (2), is described. The cis-3, 4-disubstituted cyclopentanone prepared from 7 via a sequence of reactions involving Rh (I) -catalyzed cyclization could be converted to the 3-acetylbicyclo [3.3.0] oct-2-ene skeleton, which was subjected to 1, 4-addition reaction with CN^-. The resulting cyano compound was transformed into the key intermediate 2 through appropriate modification of the substituents on the five-membered ring. This synthetic method provides a new route to carbacyclin.