Several ring expansion products carrying vinylic bromo functionality were synthesized by opening of the geminal dibromobicyclo[n.1.0]alkanes ring. Dibromocarbene was formed from bromoform and potassium tert-butoxide in hexane. Its reaction with various cyclic alkenes was the resultant dibromobicyclo[n.1.0]alkanes. Then, opening was performed using AgNO(3) in various solvent systems, such as acetic acid/DMSO, acetic acid/DMF, CH(3)OH/acetone, and H(2)O/DMF.