Synthesis of #beta#-Halobutenolides and Their Pd(0)-Catalyzed Cross-Coupling Reactions with Terminal Alkynes and Organozinc Reacgents. A General Route to #beta#-Substituted Butenolides and Formal Synthesis of cis-Whisky Lactone

摘要

An improved procedure for the efficient synthesis of #beta#-halobutenolides was developed. The Pd(0)-catalyzed coupling reactions of #beta#-halobutenolides with terminal alkynes or organozinc reagents, i.e., 1-alkenyl, aryl, and alkyl zinc reagents, to afford #beta#-substituted butenolides were carefully studied. Using the coupling protocol of #gamma#-(n-butyl)-#beta#-iodobutenolide with methylzinc halide, we performed an efficient formal synthesis of whisky lactone.