A m-Menthenone, 2-Methyl-4-siopropylcyclohex-3-en-1-one, (MICO) which possesses a cooling fragrance, is described. This compound or any one of a family of alkyl substituted analogs may be synthesized by a Lewis acid catalyzed rearrangement of 2,3-epoxycarane or its theoretically obtainable alky, substituted analogs.