Synthesis of (R)-(−) and (S)-(+)-3-(1-pyrrolyl)propyl- N-(3,5-dinitrobenzoyl)-α-phenylglycinate and derivatives. A suitable chiral polymeric phase precursor
作者:Adriana Santos Ribeiro、Alice Kanazawa、Daniela M.A.F. Navarro、Jean-Claude Moutet、Marcelo Navarro
DOI:10.1016/s0957-4166(99)00332-8
日期:1999.9
A synthetic route to obtain (R)-(−) (1), (S)-(+)-3-(1-pyrrolyl)propyl-N-(3,5-dinitrobenzoyl)-α-phenylglycinate (2) and derivatives is described. In a first step, pyrrole derivatives were prepared using the Clauson-Kaas method. The esterification, second step, was performed using basic conditions due to sensitivity of the pyrrole group toward acidic conditions. A tautomeric equilibrium involving the
获得(R)-(-)(1),(S)-(+)-3-(1-吡咯基)丙基-N-(3,5-二硝基苯甲酰基)-α-苯基甘氨酸盐的合成路线(2)和描述了派生词。第一步,使用Clauson-Kaas方法制备吡咯衍生物。由于吡咯基团对酸性条件的敏感性,使用碱性条件进行第二步的酯化反应。涉及立体发生中心的互变异构平衡诱导产物差向异构。用高度受阻的碱质子海绵®替代DMAP和Et 3 N ,可提供最终产品,且不消旋。的EE 1,2在存在光学活性Eu(tfc)3的情况下,通过1 H NMR分析确定相应的甲酯(3和4)。差向异构化没有在羧酸盐(制备观察到5 - 8)。