s<1R-(1α,4aβ,4bα,7β,10aα)>-7-(3-Formylpropanoyl)-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydro-1,4a,7-trimethyl-8-oxo-1-phenanthrencarbonsaeure-methylester 在
chromium(VI) oxide 、
硫酸 作用下,
以
丙酮 为溶剂,
以90%的产率得到(1R,4aR,4bR,7S,10aR)-7-(3-Carboxy-propionyl)-1,4a,7-trimethyl-8-oxo-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodecahydro-phenanthrene-1-carboxylic acid methyl ester