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-β-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 ...
