ethyl thioxoacetate 、
(2E,4Z)-4,5-Bis-(tert-butyl-dimethyl-silanyloxy)-penta-2,4-dienoic acid methyl ester 以
甲苯 为溶剂,
反应 2.0h,
生成 (2S,3S,6R)-5,6-Bis-(tert-butyl-dimethyl-silanyloxy)-3,6-dihydro-2H-thiopyran-2,3-dicarboxylic acid 2-ethyl ester 3-methyl ester 、 (2R,3S,6R)-5,6-Bis-(tert-butyl-dimethyl-silanyloxy)-3,6-dihydro-2H-thiopyran-2,3-dicarboxylic acid 2-ethyl ester 3-methyl ester