Stereospecificity of the formation of substituted azidotetrahydrothiophenes

Abstract

It is shown that the reaction of the four isomers of 4-methylsulfonamido-3-methylsulfonyloxy-2-(4-methoxycarbonylbutyl)tetrahydrothiophene with sodium azide leads to the formation of only a trans-3-azido-4-aminotetrahydrothiophene. Consequently, the reaction of cis-3,4-disubstituted tetrahydrothiophenes proceeds with inversion of the configuration at the C(₃) atom, whereas the reaction of trans-3,4-disubstituted tetrahydrothiophenes unusually proceeds without a change in the configuration, evidently through the intermediate formation of an aziridine ring. In addition, the reaction of 4-r-methylsulfonamido-3-t-methylsulfonyloxy-2-t(or-c)-(4-methoxycarbonylbutyl)tetrahydrothiophene with sodium azide leads to migration of the amino group from the 3 position to the 4 position with inversion of the configuration and the formation of 4-r-azido-3-t-methylsulfonamido-2-c(or t)-(4-methoxycarbonylbutyl)tetrahydrothiophene.