Stereochemical study of 1,3-N,X-heterocycles derived from α-aminoacids and formaldehyde. Structural evidence for the existence of the anomeric effect
作者:Jimmy Sélambarom、Francis Carré、Alain Fruchier、Jean Pierre Roque、André A Pavia
DOI:10.1016/s0040-4020(02)00405-2
日期:2002.5
We have shown that condensation of l-cysteine methyl ester (8) and l-threonine methyl ester (11) with formaldehyde provides a convenient and efficient access to novel heterocyclic 2:3 adducts. Depending on the amino acid, the condensation leads to either the N,N′-methylenebis(thiazolidine) (10, l-cys) or -(oxazolidine) (13, l-thr) derivative or to its bicyclo[4.4.1]undecane isomer (5, l-ser) as the
我们已经表明,L-半胱氨酸甲酯(8)和L-苏氨酸甲酯(11)与甲醛的缩合提供了方便和有效的获得新型杂环2:3加合物的途径。根据不同的氨基酸上,缩合导致要么Ñ,Ñ亚甲基双(噻唑烷)(10,L-CYS)或- (恶唑烷)(13,L -苏氨酸)衍生物或它的二环[4.4.1]十一烷异构体(5,l-ser)是反应的主要产物。的结构10,12和13通过衍射分析和/或NMR光谱法明确地确定了C 1。事实证明,后者是区分两种可能的异构体的有力工具。X射线数据强调了立体电子效应对上述化合物的结构的贡献。