Toluene-4-sulfonic acid (3S,4S,4aS,6aR,6bS,8aR,11R,12S,12aR,14aR,14bS)-4,6a,6b,8a,11,12,14b-heptamethyl-1,2,3,4,4a,5,6,6a,6b,7,8,8a,9,10,11,12,12a,14,14a,14b-icosahydro-picen-3-yl ester 在
lithium aluminium tetrahydride 作用下,
以
乙醚 为溶剂,
反应 4.0h,
生成
24-nor-urs-12-ene