(3S,4S,5R,8R,9R,10R,13S,14R,15S)-4-(2-Cyano-ethyl)-3-isopropenyl-15-isopropyl-4,9,10-trimethyl-hexadecahydro-cyclopenta[a]phenanthrene-13-carboxylic acid methyl ester 在
硒脲酸 作用下,
以
1,4-二氧六环 为溶剂,
以51 %的产率得到28-methyl ester, 3-nitrile of 23-oxo-3,4-seco-4(24)-lupene-3,28-dioic acid