1, 2, 3, 5-Tetrahydro-2-oxo-4, 1-benzoxazepine-3-acetates (5, 13, 16), 2, 3, 5, 6-tetrahydro-2-oxo-1H-4, 1-benzoazocine-3-acetates (21), and 1, 2, 3, 5, 6, 7-hexahydro-2-oxo-4, 1-benzoxazonine-3-acetate (25) were obtained from 3-[[2-(ω-hydroxyalkyl)phenyl]carbamoyl]acrylates (4, 12, 15, 20, 24) by the intramolecular Michael addition previously developed for the synthesis of 3, 4-dihydro-2H-1, 4-benzoxazine-2-acetates. In the case of 5-phenyl-3-oxo-4, 1-benzoxazepine-3-acetates (13), the 3, 5-cis and 3, 5-trans isomers were obtained in a ratio of 1 : 1. Under basic conditions, each isomer was equilibrated to a mixture of cis- and trans-13 in a ratio of 1 : 3. A deuterium exchange experiment revealed that the isomerization proceeded through the retro-Michael reaction. The stereochemistry of trans-13e was confirmed by X-ray analysis.Among the compounds (13) synthesized, N-isopropyl (cis-13c), N-benzyl (cis- and trans-13e) and N-phenethyl (cis-13f) derivatives showed considerable anxiolytic activity in the conflict test in rats.