Abstract
The structure of a new neolignan, piperenone, isolated as an insect antifeeding substance from Piper futokadzura Sieb. et Zucc. has been determined on the basis of chemical and spectral evidence. It is shown to be 5-allyl-3a, 7a-dimethoxy-2-(3, 4-dimethoxyphenyl)-3-methyl-2, 3, 3a, 6, 7, 7a-hexahydro-6-oxobenzofuran (I). Both the absolute configurations at C-2 and C-3, two of four asymmetric carbons in I are deduced to be S-arrangements.
