Stereoselective Synthesis of Quaternary Center Bearing Azetines and Their β-Amino Acid Derivatives
作者:Christopher J. MacNevin、Rhonda L. Moore、Dennis C. Liotta
DOI:10.1021/jo7018202
日期:2008.2.1
We describe here the use of a stable, four-membered azetine heterocycle for the preparation of highly substituted β-amino acid derivatives. Imidazolidinone chiral auxiliaries were found to eliminate a competitive reaction pathway that had been present under previously reported conditions for azetine synthesis. The ephedrine derived imidazolidin-2-one 21 was allowed to react as its chlorotitanium enolate
我们在这里描述了稳定的四元氮杂环丁烷杂环在制备高度取代的β-氨基酸衍生物中的用途。发现咪唑烷酮手性助剂消除了在先前报道的氮杂环丁烷合成条件下已经存在的竞争性反应途径。使麻黄碱衍生的咪唑烷基-2-酮21在优化的条件下,以其氯钛酸烯醇酯与O-甲基或-苄基肟反应,以克为单位更好地接触沸腾。还发现了这些氮杂环丁烷在完全非对映异构控制下进行烷基化,从而提供了一个四元中心。随后的苯甲酰氯开环和辅助裂解提供相应的β2,2,3-氨基羰基衍生物的收率很高。