A simple synthesis of α,β-unsaturated γ-aminobutyric acid (GABA) derivatives fron enamines

Article abstract of DOI:10.1055/s-1994-25716

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.