triethyl phosphonoacetate 、 4-O-[(3S,8S,9S,10R,13R,14S,17R)-10,13-dimethyl-17-[(2R)-6-methylheptan-2-yl]-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-yl] 1-O-(2,2,2-trichloroethyl) butanedioate 在
sodium hydride 作用下,
以
乙二醇二甲醚 为溶剂,
反应 4.0h,
以84%的产率得到5-cholesten-3β-yl ethyl butanedioate