Computational and experimental studies into NMR characterization of [2+2] cycloaddition products of norbornene

The geometry of six stereoisomers of pentacyclo[8.2.1.14,7.02,9.03,8]tetradecane formed in [2+2] cycloaddition reaction of bicyclo[2.2.1]hept-2-ene (norbornene) were optimized by a theoretical method at the DFT level with the B3LYP functional. The calculated GIAO 1H and 13C shieldings were transformed to chemical shifts (δ) on the TMS scale and next compared with those obtained experimentally for two stereoisomers. The 1H and 13C NMR chemical shifts calculated using the DFT method were found to be in very good agreement with the available experimental data. This is the first example of studying the [2+2] cycloaddition products of norbornene by theoretical method.