Aromaticity in azlactone anions and its significance for the Erlenmeyer synthesis

Chandrasekhar, Sosale and Karri, Phaneendrasai (2006) Aromaticity in azlactone anions and its significance for the Erlenmeyer synthesis. In: Tetrahedron Letters, 47 (32). pp. 5763-5766.

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Abstract

Azlactone anions-the key intermediates in the classical Erlenmeyer synthesis of amino acids-apparently possess aromatic stabilization, as indicated by the relative rate of base catalyzed deuterium exchange in the following analogs: 1-methyl-2-phenyl-5(4H)-imidazolone > 2-phenyl-5(4H)-oxazolone (azlactone) > 3,3-dimethyl-2-phenyl-4(3H)-pyrrolone. This is paralleled by the relative rate of condensation of these compounds with hexadeuteroacetone. Reported pK(a) data also suggest that the azlactone products of the Erlenmeyer synthesis are analogs of the fulvenes. (c) 2006 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	Tetrahedron Letters
Publisher:	Elsavier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Amino acid;Aromaticity;Azlactone;Deuterium exchange; Erlenmeyer synthesis;Fulvene;Hexadeuteroacetone.
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	04 Dec 2008 06:36
Last Modified:	19 Sep 2010 04:53
URI:	http://eprints.iisc.ac.in/id/eprint/16814

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