PROTON-RESONANCE SPECTRA AND SUBSTITUENT-INDUCED CHEMICAL-SHIFTS OF 3-HALOCAMPHORS

Complete signal assignments of high-field H-1 NMR spectra for 3-halosubstituted camphors (endo and exo) are presented, allowing a refinement of a previous analysis for the chloro (endo and exo) and bromo (endo) derivatives. in addition, still unpublished data for the dichloro and exo-fluoro derivatives and for three new compounds (endo-fluoro, endo- and exo-iodo), in addition to a revised assignment of the camphor parent molecule, are reported. The precise substituent-induced chemical shifts (SCS) obtained for these difunctional systems are examined on the basis of well known transmission mechanisms aided by correlations with steric and electronic parameters, and taking into account SCS data from monohaloalkanes and the calculated molecular geometry data (using the AM1 method).