Synthesis of medium-sized lactones by the copper(I)chloride/2,2′-bipyridine-catalyzed cyclization of di- and trichloroacetates
作者:Frank O.H. Pirrung、Henk Hiemstra、W. Nico Speckamp、Bernard Kaptein、Hans E. Schoemaker
DOI:10.1016/s0040-4020(01)89549-1
日期:1994.1
Medium-sized lactones (eight- to eleven-membered rings) are efficiently formed by Cu(bpy)Cl catalyzed cyclization of various alkenyl di- and trichloroacetates at temperatures between 80 and 190°C in 1,2-dichloroethane or benzene as solvents. The mechanism of the alkene addition reaction is best understood as a chlorine atom transfer process through radical type intermediates. Exclusive endo-cyclization
中性内酯(8至11元环)是通过Cu(bpy)Cl在1,2-二氯乙烷或苯中的80-190°C温度下催化各种烯基二-和三氯乙酸酯的环化反应有效形成的。最好将烯烃加成反应的机理理解为通过自由基型中间体进行的氯原子转移过程。独家内-cyclization在所有病例中观察到。十元和十一元内酯只能通过“刚性链”方法访问,在该方法中,炔烃或烯烃官能团被纳入连接反应中心的链中,从而降低了分子的柔韧性。