Abstract The 1,2-migration of an ethylthio group with inversion of configuration at the C-1 and C-2 atoms was observed during the attempted preparation of 2,3-orthoester derivatives of ethyl 1-thio-α- l -rhamnopyranoside. The rearrangement leading to the formation of methyl 2-thio-β- l -glucopyranosides could be avoided by preparing the orthoester in DMF rather than in acetonitrile and by using a controlled
摘要在尝试制备乙基1-
硫代-α-1-
鼠李糖吡喃糖苷的2,3-原酸酯衍
生物时,观察到乙
硫基的1,2-迁移,其C-1和C-2原子的构型反转。通过在
DMF中而不是在
乙腈中制备原酸酯,并通过使用可控制量的酸催化剂,可以避免导致甲基2-
硫代-β-1-
葡萄糖基
吡喃糖苷形成的重排。