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,为光学活性(1S,5R)-7,7-烷基二氧杂环[3.3.0]辛-3-酮-2-烷氧羰基,可用于合成光学活性的
卡巴环素。该中间体是从外消旋化合物(1SR,5RS)-7,7-烷基二氧杂环[3.3.0]辛-3-酮-2-烷氧羰基顺式
环己烷-3-酮的非还原化合物中,通过微
生物处理制备而成。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。