Abstract

BAILEY, William F.  and  OVASKA, Timo V.. Allylic Proton-Proton Coupling in Stereodefined Alkylidenecyclobutanes and Alkylidenecycopentanes. J. Mex. Chem. Soc [online]. 2009, vol.53, n.3, pp.139-142. ISSN 1870-249X.

Analysis of the ¹H NMR spectra of eight stereodefined alkylidenecycloalkanes allows determination of the magnitude of allylic coupling in these compounds. In contrast to the trend normally observed, the magnitude of transoid-allylic coupling was found to be invariably greater by ~0.5 Hz than the cisoid-allylic coupling. The larger transoid-allylic coupling may be attributed to the slightly smaller dihedral angle relating allylic =C-C-H plane with the C=C-C plane in the E-isomers.

Keywords : Proton NMR; Allylic Coupling; Alkylidenecycloalkanes.

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