通过非手性α-氨基异丁酸(Aib),ArSO 2-(Aib)5 -OMe(Ar =对甲苯基,对溴苯基和对甲氧基苯基)的同五肽的分子构象,堆积结构和分子间相互作用单晶X射线衍射分析。将肽折叠成3个10螺旋构象,该构象由两个或三个连续的III型或III'型十原子分子内氢键合的β-转角组成。在打包模式下,左手(M)和右手(P)3 10-螺旋分子形成具有头尾型分子间氢键的线性网络结构。根据功能基团或取代基的不同,获得了两种由同手性序列(⋯ M ⋯ M ⋯ M ⋯或⋯ P ⋯ P ⋯ P ⋯)和杂手性序列(⋯ M ⋯ P ⋯ M ⋯ P consisting)组成的网络结构。肽。有趣的是,当使用不同的结晶介质时,具有对甲苯基的肽1a结晶不同。
Unexpected alkoxyl migration in the reaction of silyl ketene acetals with p-toluenesulfonyl azide
作者:Yong Xu、Shizheng Zhu
DOI:10.1016/s0040-4020(01)00283-6
日期:2001.4
The reaction of p-toluenesulfonylazides with several silyl ketene acetals has been investigated. 1-Trimethylsilyloxy-ethylene reacted with TsN3 to give a good yield of N-p-toluenesulfonyl substituted glycinates exclusively. However, during the reaction of 1-trimethylsilyloxy-propene with TsN3, an unexpected alkoxyl migration occurred to give N-acylsulfonyl amides; other products, N-p-toluenesulfonyl