Dehalogenation of 1,3-diiodotricyclo[3.3.0.0(3,7)]octane: Generation of 1,3-dehydrotricyclo[3.3.0.0(3,7)]octane, a 2,5-methano-bridged [2.2.1]propellane

摘要

Compounds isolated from the reaction of (+/-)-1,3-diiodotricy- clo[3.3.0.0(3,7)] octane with molten sodium or tBuLi suggest the intermediate formation of (+/-)-1,3-dehydrotricyclo[3.3.0.0(3,7)] octane. Worthy of note is the formation of stereoisomeric bi(5-methylenebicyclo[2.2.1]hept-2-ylidene) derivatives, probably by coupling of two units of (+/-)-1,3-dehydrotricyclo[3.3.0.0(3,7)] octane of the same or different absolute configuration followed by fragmentation, processes that have been studied by theoretical calculations.