A benzene extract of the trunk wood of Aniba terminalis (Lauraceae) contained besides benzyl benzoate, benzyl salicylate, d, 1 -camphor and sitosterol, (2S,3S,3aR)- and (2R,3S,3aS)-3a-allyl-5 methoxy-3-methyl-2-piperonyl-2,3,3a,6-tetrahydrod-oxobenzofurans, which may be responsible, through sequential rearrangements of the Cope, retro-Claisen and Claisen types, and finally dehydrogenation, for the formation of the co-occurring (2S,3S,5S)- and (2R,3S,5R)-5-allyl-5-methoxy-3-methyl-2-piperonyl-2,3,5,6-tetrahydro-6-oxobenzofurans, the (2S,3S)-6-O-allyl-5-methoxy-3-methyl-2-piperonyl-2,3-dihydrobenzofuran, the (2S,3S)- and (2R,3S)-7-allyl-6-hydroxy-5-methoxy-3-methyl-2-piperonyl-2,3-dihydrobenzofuran and the 7-allyl-6-hydroxy-5-methoxy-3-methyl-2-piperonylbenzofuran.