C–C torsion angles in HC-CCH₃ moieties can be measured by a new NMR experiment based on the measurement of CH–CH dipolar–dipolar cross-correlated relaxation rates and is demonstrated on a mixture of ¹³C-labeled epothilone (1) and tubulin. The new pulse sequence is broadly applicable to any HC-CCH₃ moiety and therefore to a number of amino acid side chains in proteins.