3-Methyl-2-cyclohexen-1-one

Description

May be prepared by acid hydrolysis and decarboxylation of the corresponding 4-carbetoxy derivative; by oxidation of 1-methylcyclohex-l-ene with chromium trioxide in acetic acid; by cyclization of 3-carbetoxy-6-chlorohept-5-en-2-one with sulfuric acid.

Chemical properties

CLEAR VERY SLIGHTLY YELLOW TO BROWN LIQUID

Chemical properties

3-Methyl-2-cyclohexen-1-one is a nonaromatic cyclic ketone with a medicinal, phenolic, mild cherry aroma

Occurrence

Reported found in oil of Mentha pulegium, cocoa, coffee, filbert, sweet corn, dried bonito, katsuobushi, wild rice and clam. Also produced by some animals in vivo

The Uses of 3-Methyl-2-cyclohexen-1-one

3-Methyl-2-cyclohexen-1-one was used in the synthesis of 19-nor-1α, 25-dihydroxyvitamin D(3) derivatives. It was also used in sex pheromone of the Douglas-fir beetle. Used in nut flavor.

The Uses of 3-Methyl-2-cyclohexen-1-one

3-Methyl-2-cyclohexenone is an insect sex pheromone of the Douglas-fir beetle. It can be used as a starting material:

• In the total synthesis of (?)-ar-tenuifolene, a naturally occurring aromatic sesquiterpene.
• To synthesize an organic building block 2-trimethylsilyl-3-methyl-cyclohexenone.
• In the total synthesis of natural diterpenoids (+)-taiwaniaquinone H and (+)-dichroanone.

Preparation

By acid hydrolysis and decarboxylation of the corresponding 4-carbetoxy derivative; by oxidation of 1-methylcyclohex-1-ene with chromium trioxide in acetic acid; by cyclization of 3-carbetoxy-6-chlorohept-5-en-2-one with sulfuric acid.

Definition

ChEBI: 3-Methyl-2-cyclohexen-1-one is a cyclic olefin.

Aroma threshold values

Aroma characteristics at 2.0%: sweet, nutty, phenolic, walnut, fruity, almond and benzoin

Taste threshold values

Taste characteristics at 50 ppm: nutty, musty, phenolic and woody with grain-like nuances.

Synthesis Reference(s)

Journal of the American Chemical Society, 101, p. 494, 1979 DOI: 10.1021/ja00496a044
The Journal of Organic Chemistry, 42, p. 1349, 1977 DOI: 10.1021/jo00428a017
Tetrahedron Letters, 17, p. 3, 1976