7α-(ethoxycarbonyl)-15β,16β-methylene-3-oxo-17α-pregn-4-ene-21,17-carbolactone 在
2,3-二氯-5,6-二氰基-1,4-苯醌 作用下,
以
1,4-二氧六环 为溶剂,
反应 14.0h,
以32%的产率得到(1S,4a'S,4b'R,6a'R,7a'S,8a'R,8b'R,8c'R,9'S)-4a',4b',6a',7a',8a',8b',8c'-heptamethyl-2',3-dimethylene-9'-(pent-1-en-2-yl)-2',4a',4b',6',6a',7a',8',8a',8b',8c',9',10'-dodecahydro-5'H-spiro[cyclopentane-1,7'-cyclopropa[4,5]cyclopenta[1,2-a]phenanthrene]