Carboxyl-mediated Pictet-Spengler reaction. Direct synthesis of 1, 2, 3, 4-tetrahydro-. beta.-carbolines from tryptamine-2-carboxylic acids

K Narayanan, L Schindler, JM Cook

Index: Narayanan, Krishnaswamy; Schindler, Liesl; Cook, James M. Journal of Organic Chemistry, 1991 , vol. 56, # 1 p. 359 - 365

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Citation Number: 31

Abstract

The Pictet-Spengler condensation of various tryptamine-2-carboxylic acids 9a-f with carbonyl compounds in benzene/dioxane/trifluoroacetic acid (Table I) with simultaneous loss of carbon dioxide afforded directly the corresponding 1, 2, 3, 4-tetrahydro-@-carbolines 14a-j in good to excellent yields. This reaction greatly enhances the use of the Abramovitch- Shapiro method for the synthesis of highly oxygenated ring A substituted 1, 2, 3, 4- ...