(4R,5R,6R)-2,4-Bis-(2-chloro-acetoxy)-6-((R)-1,2-diacetoxy-ethyl)-5-[(2S,3S,4S,5R,6R)-3,4,5-triacetoxy-6-((S)-1,2-diacetoxy-ethyl)-tetrahydro-pyran-2-yloxy]-tetrahydro-pyran-2-carboxylic acid methyl ester 在
溴化钛(IV) 作用下,
以
二氯甲烷 为溶剂,
反应 42.0h,
以99%的产率得到(2S,4R,5R,6R)-2-Bromo-4-(2-chloro-acetoxy)-6-((R)-1,2-diacetoxy-ethyl)-5-[(2S,3S,4S,5R,6R)-3,4,5-triacetoxy-6-((S)-1,2-diacetoxy-ethyl)-tetrahydro-pyran-2-yloxy]-tetrahydro-pyran-2-carboxylic acid methyl ester