Regio- and stereoselective ring-opening reactions of cyclopropenones: α-methylene-γ-butyrolactones via additions of trichlorocyclopropenylium ions to alkenes
作者:Klaus Musigmann、Herbert Mayr、Armin de Meijere
DOI:10.1016/s0040-4039(00)88780-8
日期:1990.1
The 2-chloro-3-(2′-chloroalkyl)cyclopropenones 4, readily obtained by hydrolysis of the adducts of the trichlorocyclopropenylium ion onto alkenes, thermally rearrange to propiolic acid chlorides 6. Treatment of 4 with TosOH·H2O in CH2Cl2 yields the (E)-3-chloro-2-(2′-chloroalkyl)acrylic acids 9, which have been converted in two simple steps to α-methylene-γ-butyrolactones 11 with good overall yields
通过将三氯环丙烯基离子的加合物水解到烯烃上而容易获得的2-氯-3-(2'-氯烷基)环丙烯酮4热重排为丙酰氯6。在CH 2 Cl 2中用TosOH·H 2 O处理4产生(E)-3-氯-2-(2'-氯烷基)丙烯酸9,已通过两个简单步骤将其转化为α-亚甲基-γ -丁内酯11具有良好的总收率。