Utilization of industrial waste materials, 6. Utilization of derivatives of the bicyclic proline analog (all-R)-octahydrocyclopenta[b]pyrrol-2-carboxylic acid in the stereoselective synthesis

Abstract

Utilization of the industrial waste material benzyl (all-R)-cyclopenta[b]pyrrol-2-carboxylate 1a or its derivatives 1b, 1c as chiral auxiliaries is described. Allylation of nitrothioacetamides, proceeding by initial S-allylation followed by a facile thio Claisen rearrangement, is accomplished with a diastereomeric ratio (dr) up to 85:15 using 1a, b as auxiliaries in stoichiometric amounts. Another aspect of this report is the diastereoselective synthesis of optically active amines, starting from aldehydes, with optical purities (op) up to 99%, Again a derivative of 1a was used as source of chirality.