NMR studies on [2+3] cycloaddition of nitrile oxides to cyclohexene derivatives

Site selectivity, regioselectivity and stereoselectivity of [2+3] cycloaddition of 4-trifluoromethylbenzonitrile oxide to cyclohexene carboxylates substituted with alkenyl functions were examined. Site selectivity was correlated with electron charges of alkenyl carbon atoms. Structure of the products has been established by an extensive application of 2D H-1 and C-13 NMR spectroscopy and electrospray ionization mass spectrometry. (C) 2013 Elsevier B.V. All rights reserved.