(2RS,8aRS,10SR,10aRS,12SR)-10,12-dibenzoyloxy-2,3,4,5,6,7,8,8a,9,10-decahydro-1H-2,10a-ethanophenanthrene-8,8-dicarboxylic acid 在
硫酸 作用下,
以
氯仿 为溶剂,
反应 0.17h,
以100%的产率得到(2RS,4aSR,4bSR,8SR,8aSR,10SR,10aRS,12SR)-8-carboxy-10,12-dibenzyloxy-2,3,4,4a,4b,5,6,7,8,8a,9,10-dodecahydro-1H-2,10a-ethanophenanthrene-8,4b-carbolactone