2,3,6-Trimethylcyclohexan-1-one → Dehydrolinalool

Reaction equation

CC1C(C)CCC(C)C1=[O:10].[CH3:11][C:12](=[CH:14][CH2:15][CH:16]=[C:17]([CH3:20])[C:18]#[CH:19])[CH3:13].CC(=CCCC(=C)C#C)C>O>[CH3:11][C:12]([CH3:13])=[CH:14][CH2:15][CH2:16][C:17]([OH:10])([C:18]#[CH:19])[CH3:20]

Participants

Procedure

A mixture of 28 g of 2,3,6-trimethyl-cyclohexanone and 27 g of the isomer mixture consisting of 2,6-dimethyl-oct-2,5-dien-7-yne and 2-methyl-6-methylene-oct-2-en-7-yne, obtained by elimination of water from 2-dehydrolinalool, is added dropwise to a suspension of 35 g of KOH in 200 ml of toluene at 0° C. The reaction mixture is then kept for 6 hours at 0° C, whilst being stirred, after which water is added and the organic phase formed is dried and concentrated. Subsequent fractional distillation gives 12.3 g of unconverted trimethylcyclohexanone and 12 g of a mixture of 2,3,6-trimethyl-1-(3',7'-dimethyl-oct-1'-yn-3',6'-dien-1'-yl)-cyclohexanol and 2,3,6-trimethyl-1-(7'-methyl-3'-methylene-oct-1'-yn-6'-en-1'-yl)-cyclohexanol of boiling point 125°-127° C/0.4 mm Hg as a viscous oil. This corresponds to a yield of 39%, based on ketone converted. Fragrance note: faintly floral, spicy, minty.