Synthesis 1994; 1994(12): 1471-1475
DOI: 10.1055/s-1994-25716
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A Simple Synthesis of α,β-Unsaturated γ-Aminobutyric Acid (GABA) Derivatives from Enamines

Hans Henniges* , Chiara Gussetti, Hans-Christian Militzer, Mark S. Baird, Armin de Meijere
  • *Institut für Organische Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, D-37077 Göttingen, Germany and Department of Organic Chemistry, Universiy College of North Wales, Bangor LL57 2UW, Great Britain
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Publication History

Publication Date:
25 April 2002 (online)

Bromination of enamines 3b-g at - 78°C and subsequent treatment of the resulting iminium salts 4b-g with excess tert-butyl lithioacetate leads to tert-butyl 4-(N,N-dialkylamino)carboxylates 9b-g in good to very good yields. Ester cleavage of the dibenzylamino derivative 9d with trifluoroacetic acid yields the corresponding acid 10. Subsequent catalytic hydrogenation of 10 leads to the fully deprotected 4-amino-4-methylpentanoic acid (12) in high yield.