Department of Chemistry, University of Calcutta, 92, Acharya P. C. Road, Kolkata-700 009, India E-mail: akmitra@cucc.ernet.in Fax: 91-033-2351-9755 Manuscript received 21 January 2003, revised 30 May 2003, accepted 3 July 2003 Carbonyl compounds can be regenerated from the corresponding oximes and semirarhazones by a solvent-free, rapid, efficient and simple method under microwave irradiation exploiting copper(ll) chloride.