A new clerodane derivative, (-)-16-hydroxycleroda-3,13-dien-16,15-olide-18-oic acid, (4a alpha,6 alpha,8a alpha) 1-carboxy-5(S)-[2(2,5-dihydro-5-hydroxy-2-oxo-4-furanyl)ethyl-5,6,8a-trimethyl-3,4,4a,5,6,7,8,8a-octahydro-naphthalene was isolated as a minor component of the polar fractions of the leaves of E. grandiflorus. The structure was determined by spectroscopy (IR, MS, 1D and 2D H-1 and C-13 NMR). The absolute configuration was determined by a hemisynthesis using (+)-hardwickiic acid methyl ester, from commercial copaiba oil, as starting material. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.501117122