Nuclear magnetic resonance spectroscopy. Effects of molecular asymmetry on carbon-13 chemical shifts

Abstract

A nearby center of molecular asymmetry often induces magnetic nonequivalence of the protons of an isopropyl group (or of a methylene group), and this phenomenon has been the subject of many investigations. We report here the first observance of the effect of molecular asymmetry on the resonances of methyl carbons in isopropyl groups in compounds of the type (CH_3)_2-CH(CH_2)_nCHR_1R-2.