The measurement of ¹J_CH values from broad-band decoupled ¹³C N.M.R. spectra: application to the spectral assignment of cis-Pinan-2-ol

Abstract

¹J_CH values, together with chemical shift data and definite information on the number of protons attached to each carbon in a compound, are available from just three spin-echo Fourier-transform ¹³C n.m.r. spectra by employing the pulse sequence θ-τ-180º-τ-180º-f.i.d., in which the broad-band proton decoupler is gated off during the first delay period, and with τ values of 6, 8 and 9 ms. The experimental time required for collecting these three spectra will be somewhat less than the total time required for the usual procedures for obtaining the chemical shift data and for attempting to obtain carbon multiplicity and ¹J_CH data. Recent assignment problems with cis-pinan-2-ol are unambiguously resolved by this technique.