Synthesis 2005(16): 2723-2729  
DOI: 10.1055/s-2005-872109
PAPER
© Georg Thieme Verlag Stuttgart · New York

Syntheses of α-Amino Squaric Acids Using an Aminomalonate Equivalent Bearing a Squaryl Group

Toshikazu Ishida, Tetsuro Shinada*, Yasufumi Ohfune*
Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi 558-8585, Japan
e-Mail: shinada@sci.osaka-cu.ac.jp; e-Mail: ohfune@sci.osaka-cu.ac.jp;
Further Information

Publication History

Received 6 April 2005
Publication Date:
04 August 2005 (online)

Abstract

The synthesis of an amino acid analogue bearing a squaryl group as a carboxylic acid surrogate (sq-AA; 2) has been developed. Aminomalonate equivalent 6 was used as a nucleophilic synthon whose alkylation or conjugate addition reaction followed by deprotection and decarboxylation reaction gave sq-AAs.

15

The Sq group is sensitive to strongly basic or acidic conditions, giving a complex mixture.