Mechanistic studies on the cis to trans epimerization of trisubstituted 1,2,3,4-tetrahydro-beta-carbolines.

ABSTRACT: It is well-known that N(b)-benzyltryptophan alkyl esters undergo the Pictet-Spengler reaction with aldehydes to furnish both cis- and trans-1,2,3,4-tetrahydro-beta-carbolines, with the trans isomer predominating. Epimerization at C-1 took place under acidic conditions to produce, exclusively, the thermodynamically more stable trans diastereomer via internal asymmetric induction. Recent kinetic experiments provided insight into the cis to trans epimerization mechanism involved in the Pictet-Spengler reaction of 1,2,3-trisubstituted tetrahydro-beta-carbolines. Since the epimerization reaction had been shown to be sensitive to electronic effects at C-1, the rate data for a series of 1-phenyl-substituted 1,2,3,4-tetrahydro-beta-carbolines was investigated via a Hammett study. Analysis of the d

SUBMITTER: Van Linn ML 

PROVIDER: S-EPMC2911483 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature