Enantioselective Total Syntheses and Stereochemical Studies of All Four Stereoisomers of Yingzhaosu C
摘要:
The enantioselective total syntheses and the stereochemistry of all four stereoisomers of yingzhaosu C, an antimalarial peroxy-containing sesquiterpene isolated from yingzhao [Artabotrys uncinatus (L.) Merr.], are described. The key to the syntheses was the combination of Sharpless asymmetric epoxidation and the intramolecular nucleophilic epoxy-opening with a benzylic peroxy group to construct the 1,2-dioxane skeleton. The configurations of the 1,2-dioxanes in four stereoisomers were assigned by spectroscopy and chemical transformation.