(1S,4aR,5S,6R,8aR)-5-Carboxymethyl-6-isobutyryl-1,4a-dimethyl-decahydro-naphthalene-1-carboxylic acid methyl ester 在
三氟乙酸酐 作用下,
反应 3.0h,
以85.6%的产率得到(4aR,4bR,8S,8aR)-1-Isopropyl-4b,8-dimethyl-3-oxo-4,4a,4b,5,6,7,8,8a,9,10-decahydro-3H-2-oxa-phenanthrene-8-carboxylic acid methyl ester