An easy vinylcyclobutane–cyclohexane rearrangement
Abstract
1-(2,2-Dicyclopropylvinyl)-2,2,3,3-tetracyanocyclobutane (2a), which was obtained in the reaction of 1,1-dicyclopropylbuta-1,3-diene (1a) with tetracyanoethylene, rearranged smoothly to the cyclohexene (3a) in a polar solvent, whereas 1-(2,2-di-isopropylvinyl)-2,2,3,3-tetracyanocyclobutane (3d) fragmented into methylene-malononitrile and the diene (4).