Dakin-West Trick in the Design of Novel 2-Alkyl(aralkyl) Derivatives of Oxazolo[3,2-a]pyridines

• Main Authors: Eugene V. Babaev, Alexander A. Bush, Zeinul-Gabiden M. Kazhkenov
• Format: Article
• Language: English
• Published: MDPI AG 2005-09-01
• Series: Molecules
• Subjects: Oxazolo[3; 2-a]pyridinium salts; mesoionic oxazolo[3; 2-a]pyridinium-2-olates; munchnones; recyclization; hydrolytical cleavage of oxazolone; Dakin-West reaction
• Online Access: http://www.mdpi.com/1420-3049/10/9/1109/

A series of previously unavailable derivatives of 2-alkyl- and 2-benzylderivatives of oxazolo[3,2-a]pyridines III were obtained via tandem ring opening and ring closure from stable mesoionic 3-acyloxazolo[3,2-a]pyridinium-2-olates I. The key intermediates of this tandem transformation are N-(b-oxoethyl)pyridones-2 II obtained by Dakin-West acylation of (pyridone-2-yl-1)acetic acid. An example of further utilization of this strategy is illustrated by preparation of unknown 2-benzylimidazo[1,2-a]pyridine from the salt I and ammonia.