5-单取代丙二酸亚异丙酯的简便合成法

A Versatile Synthesis of 5-Monosubstituted Isopropylidene Malonates

5-单烃基取代的丙二酸亚异丙酯是重要的有机合成中间体,由于它的活性亚甲基具有较强的酸性(pK_a=4.75),用卤代烃直接烃化时,往往生成5,5-双取代产物,所以一般用间接方法合成5-单取代丙二酸亚异丙酯,其中以丙二酸亚异丙酯与羰基化合物缩合成亚烃基丙二酸亚异丙酯,继而还原的两步法最为普遍,常用的还原方法和还原剂有催化氢化、

Alkylidene isopropylidene malonates prepared in situ from Meldrum' s acid and carbonyl compounds in benzene were reduced directly to give monosubstituted isopropylidene malonates by sodium borohydride in the presence of phase transfer catalyst.