A process is provided for preparing (trans)-4-phenyl-L-proline derivatives with excellent stereospecificity, which are useful in preparing certain ACE inhibitors, which process involves reacting a proline derivative of the structure ##STR1## whereing R is a nitrogen protecting group, R.sub.1 is H, aryl, arylalkyl or lower alkyl, and X is a leaving group such as fluorine, an alkyl sulfonate, arylsulfonate or cycloalkyl sulfonate is reacted with an aromatic nucleophile, such as benzene, in the presence of a Lewis acid such as AlCl.sub.3 to form the (trans)-4-phenyl-L-proline derivative of the structure ##STR2##
提供了一种制备(反式)4-
苯基-
L-脯氨酸衍
生物的过程,具有优异的立体特异性,这些衍
生物在制备某些ACE
抑制剂时非常有用,该过程涉及将结构为##
STR1##的脯
氨酸衍
生物与芳香族亲核试剂反应,其中R是
氮保护基,R.sub.1是H,芳基,芳基烷基或较低的烷基,X是如
氟,烷基
磺酸盐,芳基
磺酸盐或
环烷基
磺酸盐等离子基,反应时在Lewis酸(如AlCl.sub.3)的存在下形成结构为##
STR2##的(反式)4-
苯基-
L-脯氨酸衍
生物。