(R,R)-2,2-Dimethyl-α-(trichloromethyl)-1,3-dioxolane-4-methanol 5 and its (R,S)-isomer 6 were converted into the TBDMS ethers of (2S,3R)-methyl 3-(hydroxymethyl)oxiranecarboxylate 12 and its (2R,3R)-isomer 14, respectively, with 100% stereoselectivity. threo-Glycols afforded cis-epoxides, while erythro-glycols provided the trans-isomers.
将(R,R)-2,2-二甲基-α-(三
氯甲基)-
1,3-二氧戊环-4-
甲醇5及其(R,S)-异构体6转化为(2 S,3 R)-3-(羟甲基)
环氧乙烷甲酸甲酯12及其(2 R,3 R)-异构体14,具有100%的立体选择性。苏-Glycols给予顺
环氧化物,而赤-glycols提供的反式异构体。