SYNTHESIS AND REACTIONS OF POLY[(4-CHLOROBUTYL)THIIRANE]: EVIDENCE FOR BACKBONE-ASSISTED SOLVOLYSIS†‡

(4-Chlorobutyl)thiirane is prepared in 80% yield in a single step from (4-chlorobutyl)oxirane. Homopolymerization of (4-chlorobutyl)thiirane with ZnEt₂—CH₃OH or CdCO₃ initiator systems provides poly(4-chlorobutyl)thiirane] as a soft elastomer with inherent viscosity 0.2dL/g. Reaction of poly(4-chlorobutyl)thiirane] with tetra-n-butylammonium benzoate in N,N-dimethylacetamide proceeds by direct displacement, without involvement of the backbone sulfur atom. Solvolysis under more strongly ionizing conditions (acetic acid/chloroform) occurs with repeating unit isomerization, most probably via a cyclic intermediate formed by attack of the backbone sulfur atom on the chloromethyl group at the side chain terminus.