Abstract Aminocyclopropanation of 1-ethenylcycloalkenes 2a-d with N, N-dibenzyl-and N, N- dimethylformamide, respectively, by treatment with cyclohexylmagnesium bromide in the presence of methyltitanium triisopropoxide yielded the exo-(n+ 3)-N, N-dimethylamino-1- ethenylbicyclo [n. 1.0] alkanes 3a-d (58-72%). Compounds 7b-d could be transformed by thermal vinylcyclopropane to cyclopentene rearrangement to the corresponding exo-4- ...