A Novel Synthesis of Carboxylic Acids and Lactones Having a Tertiary or a Quaternary Carbon at β-potion from a 1-Chlorovinyl p-Tolyl Sulfoxides

Abstract

Addition of the lithium enolate of carboxylic acid esters to 1-chlorovinyl p-tolyl sulfoxides, which were synthesized from chloromethyl p-tolyl sulfoxide and ketones or aldehydes in good yields, gave carboxylic acid esters having a tertiary or a quaternary carbon at the 3-position, and chlorine and sulfinyl groups at the 4-position in high to quantitative yields. The adducts were converted to various carboxylic esters having methyl, formyl, and hydroxycarbonyl groups at the 3-position. A novel method for the synthesis of γ-lactones, including spiro-type γ-lactones and α-methylene γ-lactones, was realized from the adducts in good overall yields.