Tetrahedron

An annulation method for the synthesis of alkyl-substituted 6-carbomethoxy-2-pyridones

Y Zhang, BM Loertscher, SL Castle

Index: Zhang, Yu; Loertscher, Brad M.; Castle, Steven L. Tetrahedron, 2009 , vol. 65, # 33 p. 6584 - 6590

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Citation Number: 11

Abstract

A protocol for the synthesis of 5-alkyl and 3, 5-dialkyl-6-carbomethoxy-2-pyridones was devised. Key steps include a Mannich reaction, acylation of a tosylamine, and a PPh3/TiCl4- promoted intramolecular Reformatsky-type reaction with a thioester as the electrophile. The latter process typically afforded a vinylogous thiocarbamate via elimination of water rather than the Dieckmann-type product which would have resulted from elimination of the thiol. ...