Systematic Synthesis of Multifluorinated α,α-Difluoro-γ-lactones through Intramolecular Radical Cyclization
作者:Toshiyuki Itoh、Kohei Sakabe、Kazutoshi Kudo、Hiroyuki Ohara、Yumiko Takagi、Hiroshi Kihara、Pierre Zagatti、Michel Renou
DOI:10.1021/jo982035b
日期:1999.1.1
orbital of alpha,alpha-difluoroacetyl radical occurred; this caused unsuccessful cyclization. To apply the present radical reaction, the first synthesis of both enantiomers of difluoroeldanolide, analogues of the sex pheromone of the male African sugarcane borer, has been demonstrated. Electrophysiological tests revealed that the difluorinated analogues were as active as the natural eldanolide on the
来自烯丙基O-(三甲基甲硅烷基)-α-溴-α,α-二氟乙缩醛的碳自由基可以区域特异性地环化到烯烃部分上,从而以高收率得到γ-内酯。然后将内酯转化为相应的α,α-二氟-γ-内酯。因此,通过分子内自由基环化作为关键反应,完成了多氟化α,α-二氟-γ-内酯的系统合成。半经验MO计算研究表明,α,α-二氟乙酸酯具有独特的性质,即电子在α,α-二氟乙酰基的SOMO轨道上发生了完全的离域化;这导致环化失败。为了应用目前的自由基反应,首先合成了二氟乙酰胺的两种对映体,即非洲雄性甘蔗蛀虫性信息素的类似物,已经证明。电生理学测试表明,二氟类似物在嗅觉受体上的活性与天然的艾德诺德同等。