Synthesis and olfactoric activity of side-chain modified beta-santalol analogues

Three osmophoric points have been postulated to be necessary for the sandalwood scent of beta-santalol derivatives. One of these points, close to the hydroxyl group, is highly specific on the stereochemistry and, in particular, on the molecular shape. The role of the 2-methyl group in the side chain of beta-santalol derivatives was studied by replacement through a hydrogen atom, an ethyl or an isopropyl group. It turns out that any change at the 2-methyl substituent leads to the complete loss of sandalwood odour.