(1S,4aR,5S,6R,8aR)-6-((R)-1-Hydroxy-2-methyl-propyl)-5-methoxycarbonylmethyl-1,4a-dimethyl-decahydro-naphthalene-1-carboxylic acid methyl ester 在
对甲苯磺酸 作用下,
以
苯 为溶剂,
反应 2.0h,
以95%的产率得到(1R,4aS,4bR,8S,8aR,10aR)-1-Isopropyl-4b,8-dimethyl-3-oxo-dodecahydro-2-oxa-phenanthrene-8-carboxylic acid methyl ester