Influence of reaction conditions on products of the Pictet–Spengler condensation
作者:Karolina Pulka、Aleksandra Misicka
DOI:10.1016/j.tet.2011.01.018
日期:2011.3
The Pictet–Spenglerreaction with N-protected α-amino aldehydes was found to be very sensitive to reaction conditions. The outcome of the reaction can be controlled mainly by choice of solvent. Tetrahydro-β-carbolines were obtained in apolar solvents, while in polar media octahydro-bipyrroloindoles were the main compounds. Temperature, amount of acid and reaction time also influenced the final results
The Pictet-Spengler reaction of Trp with alpha-amino aldehydes derived from L and D-amino acids was studied in terms of double stereodifferentiation. The results observed for D-amino aldehydes represent 'matched' situation (one diastereoisomer was formed) whereas with L-amino aldehydes 'mismatched' (two diastereoisomers were formed). The conformation of newly formed six-membered ring was analyzed. It was found that stable conformers were different for cis and trans isomers. (c) 2007 Elsevier Ltd. All rights reserved.