Conception, Characterization and Correlation of New Marine Odorants

Via a synthetic sequence consisting of PPA‐mediated Friedel−Crafts acylation of veratrol ( 8 ), Clemmensen reduction, demethylation with TMSI, Williamson ether synthesis employing 3‐chloro‐2‐(chloromethyl)prop‐1‐ene and in‐situ ruthenium tetroxide oxidation, numerous substituted benzo[ b ][1,4]dioxepinones 15 − 27 and 2,3‐dihydro‐1 H ‐5,9‐dioxacyclohepta[ f ]indenones 7 , 13 and 14 were prepared to study their odor−structure correlation. In the course of these studies, we discovered the extremely powerful new marine odorant 7‐(3′‐methylbutyl)benzo[ b ][1,4]dioxepin‐3‐one ( 16 ). On the basis of the measured odor threshold data, an olfactophore model was constructed that rationalizes the observed odor intensities, and indicates an aliphatic hydrophobe at a distance of 6.3 Å from the centre of the aromatic‐ring binding site. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)