New methods for synthesis of .ALPHA.,.BETA.-unsaturated carboxylic esters from carbonyl compounds using monoanions of dithiocarbonates, and dianions of ethyl mercaptoacetate and ethyl 2-mercaptopropionate.

概要

論文の詳細を見る
The lithium enolates of O-alkyl S-alkoxycarbonylmethyl dithiocarbonates and monothiocarbonates were found to be efficient reagents for the synthesis of α,β-unsaturated esters from carbonyl compounds by single-step procedure. The dianions of ethyl mercaptoacetate and ethyl 2-mercaptopropionate were successfully generated by treatment with 2.2 equivalents of lithium diisopropylamide (LDA) in the presence of N,N,N′,N′-tetramethylethylenediamine (TMEDA) at −78 °C in THF. The dianions so formed are highly reactive toward various electrophiles. The procedure leads to a novel one-pot synthesis of α,β-unsaturated carboxylic esters from carbonyl compounds.
公益社団法人日本化学会の論文