Regio- and stereoselective (3 + 2)-cycloaddition reactions of nitrones with cyclic allenes

An effective approach to access functionalized 2 H -cyclonona(deca)[ d ]isoxazoles and 15-oxo-3,10-methanobenzo[ b ][1]azacyclododecines has been developed by the reaction of N -aryl- C , C -bis(methoxycarbonyl)nitrones with cyclonona(deca)-1,2-dienes in a one-pot fashion. The reaction of N -aryl- C -(phenylcarbamoyl)nitrones with these allenes proceeds strictly regioselectively giving the mixtures of diastereomeric isoxazolidines containing a double bond at the C 4 -position of the isoxazolidine ring. The quantum chemical calculations show that the regioselectivity of these reactions is in good agreement with the reactivity indices of the considered compounds. The first example of the reaction of functionalized keto- and aldonitrones with nine- and ten-membered cyclic allenes.