(2E,4E)-2-Ethyl-5-methyl-7-((1S,4aS,8aS)-5,5,8a-trimethyl-2-methylene-decahydro-naphthalen-1-yl)-hepta-2,4-dienoic acid ethyl ester 在
三氟化硼乙醚 作用下,
以
苯 为溶剂,
反应 48.0h,
以37%的产率得到ethyl (2E)-2-[[(1S,4aR,4bS,8aS,10aR)-2,4b,8,8,10a-pentamethyl-4,4a,5,6,7,8a,9,10-octahydro-1H-phenanthren-1-yl]methylidene]butanoate