The steric course of the reactions of 2,3-dihalotetrahydropyrans with grignard reagents
作者:Giancarlo Berti、Giorgio Catelani、Luigi Monti、Giovanni Ventresca
DOI:10.1016/s0040-4020(01)87552-9
日期:1986.1
The steric course of some reactions of 2,3-dihalotetrahydropyrans with sodium methoxide and with methyl- and phenyl-magnesium bromides has been reinvestigated. Whereas the methanolysis of the - and -dichlorides occurs with practically complete inversion, it has been confirmed that their reactions, as well as those of the dibromides, with methyl-magnesium bromide are non-stereospecific, yielding mixtures
对2,3-二卤代四氢吡喃与甲醇钠以及甲基和苯基镁溴化物的某些反应的空间过程进行了重新研究。尽管-和-二氯化物的甲醇分解几乎完全被转化,但已经证实它们和二溴化物的反应与甲基溴化镁是非立体特异性的,生成-和-3-卤代的混合物-2-甲基-四氢吡喃的比例与起始二卤化物的构型无关。进一步确定,格氏试剂在反应中引起-和-二卤化物混合物的平衡,该反应比格氏试剂偶联步骤快得多。