Spectroscopic characterization of 1-methylene-2-vinylcyclopropane and some of its derivares

Article abstract of DOI:10.1002/recl.19871060203

The characteristic NMR and vibrational spectroscopic properties of 1-methylene-2-vinylcyclopropane 1 and some of its derivatives are described and discussed.The exocyclic C=C stretching vibration is consistently found at 1745 cm^-1.The 1H NMR spectra show coupling patterns among the methylene and ring protons that are essentially independent of the substituents.The coupling constant between H-2 and the α-proton of the substituent depends on the conformation. 13C chemical shifts and coupling constants are readily interpreted using common substituent effect rules.MNDO calculations provide proton-proton distances and both orders which are used to interpret proton relaxation rates and proton-proton coupling constants.