Halogeno-1,4-dioxans and their derivatives. Part VIII. Direct replacement of chlorine in 2,3-dichloro-1,4-dioxan by sulphur and by nitrogen. Conformations of the products, of a rigid cis-fused hexahydro-1,4-dioxino[2,3-b][1,4]dioxin, and of bi-1,3-dithian-2-yl

Abstract

The preparation of SS′-(1,4-dioxan-2,3-diyl)dithiouronium dichloride and of 2,3-bis-(N-methyl-p-tolyl-sulphonylamino)-1,4-dioxan is described. Analysis of ¹H n.m.r. spectra shows these compounds to be trans-isomers, with the former having a rigid conformation. ¹H N.m.r. parameters obtained by rigorous analysis are reported for two (–)-hexahydro-1,4-dioxino[2,3,-b][1,4]dioxin-2,3-dicarboxylate esters and for bi-1,3-dithian-2-yl.