Heck arylation of N-acyl-3-pyrrolines and an N-acyl-tetrahydropyridine with aryldiazonium tetrafluoroborates under phosphine-free conditions proceeded smoothly to give alpha-hydroxycarbamates (hemiaminals) or alpha-alkoxycarbamates which were oxidized to the desired gamma- and delta-lactams. Acidic hydrolysis of the gamma-lactams produced a series of arylated GABA derivatives, including baclofen, a useful therapeutic drug. in only three steps with ail overall yield of 63 76%, Starting from N-acyl-tetrahydropyridine, aryl-delta-lactams and higher homologues of baclofen can be obtained. (C) 2002 Elsevier Science Ltd. All rights reserved.435741744