ChemInform Abstract: Cesium (Z)‐2‐Carbomethoxyethenethiolate: A Reagent for the Preparation of (Z)‐2‐Carbomethoxyethenyl Thioethers Including Selected Cysteine and Homocysteine Derivatives.

Abstract

Amino acids U 0400Cesium (Z)-2-Carbomethoxyethenethiolate: A Reagent for the Preparation of (Z)-2-Carbomethoxyethenyl Thioethers Including Selected Cysteine and Homocysteine Derivatives. -The cesium salt of the (Z)-enethiolate (III) is introduced as a new reagent for the synthesis of various 2-carbomethoxyethenyl thioethers. The (Z) stereochemistry is retained at low temperature. Secondary halides such as (IX) do not give the expected products. The reaction can be adapted to base-sensitive cysteine derivatives such as (XVII) and to homocysteine derivatives such as (XIX). In contrast, the direct addition of a thiol to methyl propiolate (I) leads to a complex mixture. -(O'DONNELL, J. S.; SINGH, S. P.; METCALF, T. A.; SCHWAN*, A. L.; Eur. J. Org. Chem. 2009, 4, 547-553; Dep. Chem., Univ. Guelph, Guelph, Ont. N1G 2W1, Can.; Eng.) -Kieslich 22-191