Synthesis 2011(9): 1435-1441  
DOI: 10.1055/s-0030-1259987
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Multisubstituted α,β-Unsaturated γ-Lactones from 1-Chlorovinyl p-Tolyl Sulfoxides and tert-Butyl Carboxylates Using Pummerer-Type Cyclization as the Key Reaction

Takashi Katae, Shimpei Sugiyama, Tsuyoshi Satoh*
Graduate School of Chemical Sciences and Technology, Tokyo University of Science, Ichigaya-Funagawara-machi 12, Shinjuku-ku, Tokyo 162-0826, Japan
Fax: +81(3)52614631; e-Mail: tsatoh@rs.kagu.tus.ac.jp;
Further Information

Publication History

Received 20 January 2011
Publication Date:
01 April 2011 (online)

Abstract

The addition reaction of 1-chlorovinyl p-tolyl sulfoxides, derived from aldehydes and chloromethyl p-tolyl sulfoxide, with the lithium enolate of tert-butyl carboxylates gave adducts in quantitative yields. Treatment of the adducts with trifluoroacetic anhydride in the presence of sodium iodide resulted in the formation of γ-lactones bearing a p-tolylsulfanyl group at the γ-position through Pummerer-type cyclization. Oxidation of the sulfanyl group to the sulfinyl group followed by thermal syn-elimination gave α,β-unsaturated γ-lactones (γ-butenolides) in moderate to good yields. Trapping the intermediates of the addition reaction with iodoalkanes gave alkylated adducts, from which α,γ- and β,γ-disubstituted γ-butenolides were obtained. These procedures provide a good way to synthesize multisubstituted γ-butenolides from aldehydes.