The oxidation products of three Rauwolfia alkaloids having yohimbane skeleton, namely, reserpine, rescinnamine and ajmalicine have been characterised by chromatographic and spectroscopic techniques. The Rf values of the oxidation products (3, 4-dehydro derivatives) in several solvent systems and the spectral data on UV, IR, NMR and fluorescence characteristics have been determined to confirm the structure of these compounds.