A novel regio- and stereospecific hydrohalogenation reaction of 2-propynoic acid and its derivatives
摘要:
2-Propynoic acid and its derivatives are hydrohalogenated regio- and stereospecifically by reaction with lithium halides in acetic acid, or preferably with 1 equiv of acetic acid in refluxing CH3CN, to afford the thermodynamically unfavorable (Z)-3-halopropenoic acids and their derivatives as sole products. A rationale for the regio- and stereospecificity is briefly discussed.