Stereoselektive epoxidierung von di-[3-O-(1,2:5,6-diisopropyliden)-α-D- und α-L-glucofuranosyl]-3,6-hexanooxepin-4,5-dicarboxylat
摘要:
Epoxidation of the oxepine diester (-)-1a leads to the oxirane (+)-2a with (S,S) configuration in high yield. (+)-1b on the other hand gives the (1aR,6R)-oxirane (-)-2b. (+)-2a undergoes photochemical ring closure to give (+)-(S,S,S,S)-3a in 90% yield.