[摘要]:2-Ethoxy carbonylcyclopentanone (1) has been brominated to yield 2-bromo-2-ethoxy carbonylcyclopentanone (2) which on further reaction with substituted thiosemicarbazones, thiocarbohydrazones, thiocarbamides and carbamides has furnished 1-thia-3,4-diaza-5,7-dioxo-2-[(substituted benzylidine)-amino]spiro[4.5]dec-2-ene (3ae), 1-thia-3,4-diaza-5,7-dioxo-2-[(substituted benzylidine)-hydrazino] spiro[4.5]dec-2-ene (4ae), 1-thia-3-aza-2-(substituted imino)-4,6-dioxo-spiro[4.4]nonane (5af) and 1-oxa-3-aza-2-(substituted imino)-4,6-dioxo-spiro[4.4]nonane (6ag) respectively. The structures of the compounds have been elucidated on the basis of spectral analysis.