Abstract: The feasibility of inducing two HBr eliminations from 4, 6-dibromo-2-bicyclo [3.1. O] hexene (3) was explored as a route to bicyclo (3.1. O] hexatriene (1). Depending on the base employed 3 was converted to bromobenzene or 6-substituted fulvenes. To elucidate the mechanism by which the fulvene arose, 3 was synthesized specifically labeled with deuterium, I3C, and alkyl groups. The labeling results require the formation of triene 1 as a ...