New intermediate, an optically active (1S,5R)-7,7-alkylenedioxy-2-alkoxycarbonylbicyclo[3.3.0]octan-3-one which is useful for the synthesis of an optically active carbacyclin. This intermediate is prepared, as a non-reduced compound, from a racemic compound, (1SR,5RS)-7,7-alkylenedioxy-2-alkoxycarbonyl-cis-bicyclo[3.3.0]octane-3-on e, by treatment of the racemic compound with a microorganism. The microorganism has an ability of specifically reducing the keto group of the (1R,5S) epimer of the racemic compound.
新的中间体是一种光学活性的(1S,5R)-7,7-烷基二氧基-2-烷氧羰基-
三环[3.3.0]辛-3-酮,可用于光学活性碳环
前列腺素的合成。这种中间体是从外消旋化合物(1SR,5RS)-7,7-烷基二氧基-2-烷氧羰基-顺式-
三环[3.3.0]
辛烷-3-酮经微
生物处理而制备的非还原化合物。该微
生物具有特异性还原外消旋化合物的(1R,5S)异构体的酮基的能力。