Synthesis of 9-N-Cinchona Alkaloid Peptide Hybrid Derivatives: Preparation and Conformational Study of 9-N-Acylamino(9-deoxy)cinchona Alkaloids

摘要

The synthesis and conformational analyses of several 9-N-acylamino(9-deoxy)cinchona alkaloids is presented. Peptides were connected to cinchona alkaloids via a 9-amino group. The synthesis of the new cinchona alkaloid derivatives was performed straightforwardly from 9-amino(9-deoxy)dihydroquinidine via coupling with carboxylic acid chlorides and several dipeptides. Both alkaloid derivatives with the configuration of the corresponding natural product as well as its unnatural epimer were studied. The conformations of the prepared derivatives in solution were determined by NMR spectroscopy. It is shown that the conformation is strongly influenced by the configuration at the 9-position.