Study on the synthetic reactions of sulfones

Abstract

A convenient synthesis of alpha-methyl vinyl sulfones was depicted. The dilithioethyl phenyl sulfone had been used to prepare the phosphorylated anion by treatment with diethyl phosphorochloridate; subsquent condensation with a carbonyl compound gave a alpha-methyl vinyl sulfones via the Horner- Emmons reaction in one-pot. alpha-Sulfenylated sulfones were obtained by the reaction of alpha-lithiosulfones with disulfide. In the case of using diphenyldisulfide as a sulfenylating agent, LiSPh generated in situ acted as the reductant which reduced the over-sulfenylated sulfones to mono- sulfenylated sulfones. 2,4-Disubstituted furans were obtained by dehydroiodination and dehydrosulfonylation and subsequent in situ isomerization of 2-iodoalkyl-4- phenylsulfonyltetrahydrofurans which were prepared from intramolecular iodine-induced etherification of beta-phenylsulfonyl-gama,delta-unsaturated alcohols. Vinyl sulfones were obtained from beta-hydroxy sulfones which had been prepared from beta-bromo alcohols via sulfenylation with thiophenol, oxidation of sulfide, and dehydration. bata-amino-alpha,alpha-dichloro sulfones were obtained in good yield from vinyl sulfones in the presence of amine, excess of sodium hydride, and carbon tetrachloride in room temperature. This reaction would involve Michael addition of amins and alpha,alpha-dichlorination in one-pot.