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-1H-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 A from the centre of the aromatic-ring binding site. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)