Structure-Odor Relationships in Monoterpenelactones

Abstract

Twelve γ-, δ- and ε-monoterpenelactones were synthesized, with seven compounds (5, 6, 7, 8, 13, 13', and 15) being newly formed. The odor of the monoterpenelactones was found to be dependent on the size of their rings and their conformation. Substitution of the equatorial methyl group at C(3) in the δ- and ε-monoterpenelactones with a planar molecular shape was necessary for the monoterpenelactones to produce a pronounced maple-tike odor.