cis-exo-2,3-dihydroxy-6-methoxycarbonyl-7-oxabicycloheptane 、
2,2-二甲氧基丙烷 在
对甲苯磺酸 calcium chloride 作用下,
以
丙酮 为溶剂,
反应 1.0h,
生成
Methyl (1R,2R,3S,4S,5R)-2,3-O,O-isopropylidene-2,3-dihydroxy-7-oxabicyclo<2.2.1>heptane-5-carboxylate 、 Methyl (1R,2R,3S,4S,5R)-2,3-O,O-isopropylidene-2,3-dihydroxy-7-oxabicyclo<2.2.1>heptane-5-carboxylate