Ring Expansion of 2‐(α‐Hydroxyalkyl)azetidines: A Synthetic Route to Functionalized Pyrrolidines
作者:François Durrat、Monica Vargas Sanchez、François Couty、Gwilherm Evano、Jérôme Marrot
DOI:10.1002/ejoc.200800316
日期:2008.7
A series of 2-(α-hydroxyalkyl)azetidines synthesized from enantiomerically pure β-amino alcohols and presenting various patterns both on the four-membered ring and on the adjacent hydroxy group were treated with either thionyl chloride or methanesulfonyl chloride in the presence of triethylamine. The thus-prepared 2-(α-chloro- or α-methanesulfonyloxyalkyl)azetidines were shown to rearrange stereospecifically
在三乙胺存在下,用亚硫酰氯或甲磺酰氯处理由对映体纯 β-氨基醇合成的一系列 2-(α-羟烷基)氮杂环丁烷,并在四元环和相邻羟基上呈现各种模式. 如此制备的 2-(α-氯-或 α-甲磺酰氧基烷基) 氮杂环丁烷显示立体定向重排成 3-(氯-或甲磺酰氧基) 吡咯烷。当这种重排在添加的亲核试剂(NaN3、KCN、KOH 或 NaOAc)存在下进行时,产生的吡咯烷会在 C-3 立体特异性地结合添加的亲核试剂。形成的吡咯烷中取代基的相对构型与中间体双环氮丙啶离子形成的机制一致,它在桥头碳原子上区域选择性地打开。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)