乙醛酸乙酯 、
[(E)-(S)-4-Benzyloxy-4-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-1-methylene-but-2-enyloxy]-tert-butyl-dimethyl-silane 在
[Co
2{(S,S)-(+)-salen}] 作用下,
以
二氯甲烷 为溶剂,
生成 (2S,6R)-6-[(S)-Benzyloxy-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-methyl]-4-(tert-butyl-dimethyl-silanyloxy)-3,6-dihydro-2H-pyran-2-carboxylic acid ethyl ester 、 (2R,6S)-6-[(S)-Benzyloxy-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-methyl]-4-(tert-butyl-dimethyl-silanyloxy)-3,6-dihydro-2H-pyran-2-carboxylic acid ethyl ester 、 (E)-(S)-7-Benzyloxy-2-(tert-butyl-dimethyl-silanyloxy)-7-((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-4-oxo-hept-5-enoic acid ethyl ester