Compounds 7-8, monoterpenic analogues of the marine metabolites puupehenone (1) and puupehedione (2), were prepared from the easily available beta-cyclocitral (10) and the aryllithium derived from 11 and 12. 8 showed antitumoral activity 4-10 times higher than that for the natural products. (C) 1998 Elsevier Science Ltd. All rights reserved.