溴乙酸乙酯 、 (1S,4aS)-7-Acetyl-6-hydroxy-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octahydro-phenanthrene-1-carboxylic acid methyl ester 在
potassium carbonate 作用下,
以15%的产率得到2-ethoxycarbonyl-7(β)-methoxycarbonyl-3,7(α),10a(β)-trimethyl-5,6,6a,7,8,9,10,10a-octahydrophenanthro<3,2-b>furan