Highly diastereoselactive synthesis of chimeras of proline and glutamate

Abstract magnified image Azomethine ylides have been generated from aromatic aldimines of α‐amino acid methyl esters under treatment with LiBr/Et 3 N and trapped with tert ‐butyl acrylate yielding racemic orthogonally protected cis ‐5‐arylpyrrolidine‐2,4‐dicarboxylates regio‐ and stereo‐selectively in high yields. Subsequent N ‐methylation and deprotection of 4‐carboxylic group of cycloaddition products led to novel prolineglutamate cis ‐chimeras with substituents at 2 and 5 positions of pyrrolidine scaffold.