13C nuclear magnetic resonance spectra of some ergosta-dienes and -trienes

Abstract

The natural abundance ¹³C spectra of several ergosta-dienes and -trienes, measured at 25·2 MHz, have been completely assigned by using off-resonance decoupling, acetylation shifts, and lanthanide-induced shifts. The effect of functional groups on the chemical shifts is highly sensitive to the environments of the functional group and the carbon atom under consideration, and analogies from simpler systems (e.g. cyclohexanes) are not always reliable.