Several (R*, S*)-1-alkyl-3-hydroxy-2-phenylazetidines (1) were synthesized by the reaction of (R*, R*)-2-(1-bromobenzyl)oxirane (2a) with aliphatic primary amines in good yields. By the reaction of (R*, S*)-2-(1-bromobenzyl)oxirane (2b), only (R*, R*)-2-aminomethyl-3-phenyloxirane (3) was obtained. Also, the reaction of (R*, R*)-2-(1-bromobenzyl)-2-methyloxirane (2c) gave a mixture of (R*, S*)-3-hydroxy-3-methyl-2-phenylazetidine (4) as the major product and (R*, S*)-2-aminomethyl-2-methyl-3-phenyloxirane (5) as the minor product.
Stereoselective synthesis of 3-hydroxyazetidines via regioselective halogenation of 2,3-epoxyamines by using magnesium bromide
作者:Michinori Karikomi、Kouji Arai、Takashi Toda
DOI:10.1016/s0040-4039(97)01360-9
日期:1997.8
A novel stereoselectivesynthesis of 3-hydroxyazetidines starting from 2,3-epoxyamines is described. Regioselectivity of the intramolecular cyclization of 2,3-epoxyamines is controlled by the use of magnesium bromide. The cyclization proceeds with retention of the stereochemistry, caused by double inversion of two sequential SN2 reactions of the epoxyamines.
描述了从2,3-环氧胺开始的3-羟基氮杂环丁烷的新颖的立体选择性合成。通过使用溴化镁来控制2,3-环氧胺的分子内环化的区域选择性。由于环氧胺的两个连续S N 2反应的两次反转,环化过程将保留立体化学。