作者:Hans Schick、Hartmut Schwarz、Angelika Finger、Sigfrid Schwarz
DOI:10.1016/0040-4020(82)85114-4
日期:1982.1
preferentially yield products of C-alkylation. Dipolar aprotic solvents favour O-alkylation; water favours C-alkylation. On the basis of these results procedures for the prepartion of 2-allyl-2-methyl-, 2-allyl-2-ethyl-, 2-methyl-2-propargyl- and 2 - benzyl - 2 - mehtyl - cyclopentane - 1,3 - dione have been developed. The alkylation of 2 - methyl - cyclopentane - 1,3 - dione with methyl bromoacetate was also
2-甲基-环戊烷-1,3-二酮的碱金属盐与烷基卤化物的烷基化的区域选择性在很大程度上取决于烷基化试剂的结构和反应中所用溶剂的类型。除甲基碘外,未取代的饱和伯烷基卤化物优先产生O-烷基化的产物。带有SP 2的烷基卤化物在β-位上的-或sp-杂化碳原子优先产生C-烷基化的产物。偶极非质子溶剂促进O-烷基化;水有利于C-烷基化。根据这些结果,制备2-烯丙基-2-甲基-,2-烯丙基-2-乙基-,2-甲基-2-炔丙基-和2-苄基-2-甲基-甲基-环戊烷的制备方法, 3-二酮已经开发出来。还对2-甲基-环戊烷-1,3-二酮与溴乙酸甲酯的烷基化进行了深入研究。