-OXOHEXAHYDROINDOLIZINO[8,7-B]INDOLE-5-CARBOXYLATE DERIVATIVES AS NEWSCAFFOLDS FOR MIMICKING BETA-TURN SECONDARY STRUCTURES - MOLECULAR-DYNAMICS AND STEREOSELECTIVE SYNTHESIS

Highly constrained -oxohexahydroindolizino[8-7-b]indole-5-carboxylate derivatives of general formula 1 have been developed as novel beta-tur n mimetics. Molecular dynamics studies on model structures 2a and 2b h ave revealed that both indolizinoindole derivatives are able to adopt conformations close to those of ideal type II' beta-turn. The asymmetr ic synthesis of this heterocyclic system was accomplished from 1,3-di- and 1,2,3-trisubstituted tetrahydro-beta-carbolines, which were prepa red in stereoselective or stereospecific way by application of the Pic tet-Spengler reaction.