抄録
The orientation and relative strength of participation of neighboring groups during the formation of azoline ring by treatment of N-thiobenzoyl, N-benzoyl, and N-benzimidoyl derivatives of dl-2-aminocyclohexanols and dl-2-aminohexanethiols with phosphorus pentoxide or thionyl chloride were comparatively examined with the reaction products obtained (Table I and II). The relative intensity was found to be in the descending order of thiobenzoyl, benzoyl, and benzimidoyl by treatment with phosphorus pentoxide and in the descending order of benzoyl, thiobenzoyl and benzimidoyl in the case of thionyl chloride. Participation of SH group to Cα (cf. Chart 1) is stronger than that of OH group. Acyl migration from N to O or N to S was examined and it was found that in N-acylated derivatives of dl-2-aminocyclohexanol all the derivatives tested underwent retention to give O-benzoyl derivative. In N-benzoylated compound of dl-2-aminocyclohexanethiol, this was retention and the trans compound gave S-benzoate, while cis compound produced only cis-thiazoline.
