Ruthenium-catalyzed [2+ 2] cycloaddition reactions of a 2-oxa-3-azabicyclo [2.2. 1] hept-5- ene with unsymmetrical alkynes were investigated. Yields of up to 90% were obtained though regioselectivity was modest. Select cycloadducts could be separated and used to access a highly functionalized [3.2. 0] bicyclic structure through reductive cleavage of the N– O bond. These ring-opened products displayed a chemical exchange phenomenon in 1D ...
