(3β,18α)-methyl 3-hydroxy-11-oxoolean-12-30-oate 、
3,4-二-O-乙酰-1,5-酐-2,6-双脱氧-L-阿拉伯-己-1-糖醇 在
iodonium di(2,4,6-trimethylpyridine) perchlorate 、 4 A molecular sieve 作用下,
以
二氯甲烷 为溶剂,
反应 4.0h,
以85%的产率得到methyl (2S,4aS,6aR,6aS,6bR,8aR,10S,12aS,14bS)-10-[(2R,3R,4R,5S,6S)-4,5-diacetyloxy-3-iodo-6-methyloxan-2-yl]oxy-2,4a,6a,6b,9,9,12a-heptamethyl-13-oxo-3,4,5,6,6a,7,8,8a,10,11,12,14b-dodecahydro-1H-picene-2-carboxylate