5-((S)-2,2-Dibenzyl-[1,3]dioxolan-4-yl)-5H-furan-2-one 、 tert-Butyl-[5-((S)-2,2-dibenzyl-[1,3]dioxolan-4-yl)-furan-2-yloxy]-dimethyl-silane 在
tris{3-(heptafluoropropylhydroxymethylene)-(+)-camphorato}europium(III) 作用下,
以
neat (no solvent) 为溶剂,
反应 22.0h,
生成
(1S,4S)-1-(tert-Butyl-dimethyl-silanyloxy)-4-((S)-2,2-dibenzyl-[1,3]dioxolan-4-yl)-7-oxa-bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylic acid dimethyl ester 、 (1R,4R)-1-(tert-Butyl-dimethyl-silanyloxy)-4-((S)-2,2-dibenzyl-[1,3]dioxolan-4-yl)-7-oxa-bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylic acid dimethyl ester