Diastereoselective Synthesis of 2-Amino-4-phosphonobutanoic Acids by Conjugate Addition of Lithiated Schöllkopf's Bislactim Ethers to Vinylphosphonates
作者:María Ruiz、M. Carmen Fernández、Aniana Díaz、José M. Quintela、Vicente Ojea
DOI:10.1021/jo034707q
日期:2003.10.1
Conjugate additions of lithiated bislactim ethers derived from cyclo-[Gly-Val] and cyclo-[Ala-Val] to alpha-, beta-, or alpha,beta-substituted vinylphosphonates allow direct and stereoselective access to a variety of 3- or 4-monosubstituted and 2,3-, 2,4-, or 3,4-disubstituted 2-amino-4-phosphonobutanoic acids (AP4 derivatives) in enantiomerically pure form. The relative stereochemistry was assigned
将衍生自环-[Gly-Val]和环-[Ala-Val]的锂化双lactimin醚与α-,β-或α,β-取代的乙烯基膦酸酯共轭加成可直接和立体选择性地获得各种3-或4对映体纯形式的-单取代和2,3-,2,4-或3,4-二取代的2-氨基-4-膦酰基丁酸(AP4衍生物)。通过X-射线衍射分析或1,2-氧杂磷杂环丁烷衍生物的NMR研究确定相对立体化学。调用竞争性的八元“紧凑”和“松弛”过渡态结构以合理化共轭添加物的立体化学结果。