A new procedure for the cyclopropanation of α,β-unsaturated carbonyl compounds and related systems is described which employs triisopropylsulfoxonium tetrafluoroborate and sodium hydride in dimethylformamide. Using this reagent, a range of α,β-unsaturated ketones (and an ester and a vinyl nitro example) has been converted into the corresponding gem-dimethylcyclopropyl carbonyl compounds; in addition, a preliminary result is described in which an activated alcohol is converted directly into a gem-dimethylcyclopropyl ketone by a one-pot tandem oxidation-cyclopropanation sequence, albeit in low yield.
本文描述了一种新的
环丙烷化反应,用于处理α,β-不饱和羰基化合物和相关体系,该反应在二甲基甲酰胺中使用
三异丙基磺酸鎓四
氟硼酸盐和氢化
钠。使用这种试剂,一系列α,β-不饱和酮(以及酯和
乙烯基硝基化合物)被转化为相应的gem-二甲基环丙基羰基化合物;此外,本文还描述了一种初步结果,即通过一锅串联氧化-
环丙烷化反应,将活化的醇直接转化为gem-二甲基环丙基酮,尽管产率较低。