N-Boc-L-缬氨酸 、
(2aR,3R,4S,5aS,5bS,7S,7aR,9S,11aR,12aS)-4,7-dimethoxy-3-((2R,5S)-5-(2-methoxypropan-2-yl)-2-methyltetrahydrofuran-2-yl)-2a,5a,8,8-tetramethyltetradecahydro-1H,12H-cyclopenta[a]cyclopropa[e]phenanthren-9-ol 在
五氟苯酚 、
N,N'-二异丙基碳二亚胺 、
4-二甲氨基吡啶 作用下,
以
二氯甲烷 为溶剂,
反应 48.0h,
以96%的产率得到(2aR,3R,4S,5aS,5bS,7S,7aR,9S,11aR,12aS)-4,7-dimethoxy-3-((2R,5S)-5-(2-methoxypropan-2-yl)-2-methyltetrahydrofuran-2-yl)-2a,5a,8,8-tetramethyltetradecahydro-1H,12H-cyclopenta[a]cyclopropa[e]phenanthren-9-yl (tert-butoxycarbonyl)-L-valinate