(2R,3R,4S,5R,6R,8R)-3-Acetoxy-5-(2-chloro-acetoxy)-9-hydroxy-2,4,6,8,10-pentamethyl-11-oxo-tridecanoic acid methyl ester 在
对甲苯磺酸 、 calcium chloride 作用下,
以
丙酮 为溶剂,
以70%的产率得到(E)-(2R,3R,4S,5R,6R,8R)-3-Acetoxy-5-(2-chloro-acetoxy)-2,4,6,8,10-pentamethyl-11-oxo-tridec-9-enoic acid methyl ester