The synthesis of isomeric 4-prolinylamines and 4,4 '-diprolinylamines

Starting from the previously described tert-butyl eaters of 4-epimeric N-be nzyioxycarbonyl-4-hydroxyprolines and N-benzyloxycarbonyl-4-trans and 4-cis -trifluoroacetamidoproline tert-butyl eaters, the corresponding un protecte d 3-aminoprolines and a number of their partially protected derivatives wer e synthesized via the intermediate 4-O-mesyl and 4-azide derivatives. The r eductive amination of N-benzyloxycarbonyl-4-oxoproline tert-butyl ester wit h ammonium acetate led to N-benzyloxycarbonyl-4-cis-4'-cis- and 4-cis-4'-tr ans-diprolinylamines. The H-1 NMR and CD spectra of the synthesized compoun ds are described.