ethyl (7R)-7-[(3R,3aS,5aR,5bR,7aS,11aS,11bR,13aR,13bS)-5a,5b,8,8,11a,13b-hexamethyl-1,2,3,3a,4,5,6,7,7a,9,10,11,11b,12,13,13a-hexadecahydrocyclopenta[a]chrysen-3-yl]-4-oxooct-2-ynoate 在
(R)-B-methyl-4,5,5-triphenyl-1,3,2-oxazaborolidine 、 B2H6-THF 作用下,
以
四氢呋喃 为溶剂,
反应 1.0h,
以90%的产率得到ethyl (4R,7R)-7-[(3R,3aS,5aR,5bR,7aS,11aS,11bR,13aR,13bS)-5a,5b,8,8,11a,13b-hexamethyl-1,2,3,3a,4,5,6,7,7a,9,10,11,11b,12,13,13a-hexadecahydrocyclopenta[a]chrysen-3-yl]-4-hydroxyoct-2-ynoate