Regioselective reaction of Grignard reagents in the presence of a copper(I) catalyst or of organocuprates with the terminal vinyl carbon of β-isopropenyl-β-propiolactone through the SN2′ pathway affords 4-methyl-3-alkenoic acids in which the (E)-isomers predominate in good yields. Synthetic utility of this reaction is demonstrated in one-step synthesis of homoterpenoic carboxylic acids.
在铜 (I) 催化剂或有机铜酸盐存在下,格氏试剂与 β-异丙烯基-β-丙内酯的末端乙烯基碳通过 SN2' 途径发生区域选择性反应,得到 4-甲基-3-链烯酸,其中 (E )-异构体以良好的产率占优势。该反应的合成效用在高萜羧酸的一步合成中得到证明。