Beta-Santalol (bS)

β-Santalol is an organic compound that is classified as a sesquiterpene. It comprises about 20% of the oil of sandalwood, the major component being α-santalol. As of 2002, about 60 tons of sandalwood oil are produced annually by steam distillation of the heartwood of Santalum album.
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.