Synthesis 2005(3): 493-495  
DOI: 10.1055/s-2004-834865
PSP
© Georg Thieme Verlag Stuttgart · New York

A Simple Procedure for the Transformation of l-Glutamic Acid into the Corresponding γ-Aldehyde

Manuela Rodriquez, Maurizio Taddei*
Dipartimento Farmaco Chimico Tecnologico, Università degli Studi di Siena, Via A. Moro, 53100 Siena, Italy
Fax: +39(0577)234333; e-Mail: [email protected];
Further Information

Publication History

Received 1 June 2004
Publication Date:
21 October 2004 (online)

Abstract

2-Dibenzylamino-5-oxopentanoic acid benzyl ester has been obtained in good yields by complete benzylation of l-glutamic acid in NaOH and Na2CO3, selective reduction of the γ-ester into alcohol with DIBAL and further transformation into aldehyde using Swern oxidation. The overall three-step procedure from Glu gave aldehyde in 49% yield.

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9

The use of ionic liquids in reductive amination will be reported elsewhere.

12

When DIBAL came from a new bottle, 2 equiv were sufficient to obtain good yields. When DIBAL came from a previously opened bottle, we found that it was better to use 3 equiv. It is also possible to make further additions of DIBAL at 0 °C until the starting material disappears.