2,6-Dimethyl-5-hepten-1-al was identified in
ginger. It is a yellow liquid with a powerful, green, cucumber-like, and melon
odor. It can be prepared by Darzens reaction of 6-methyl-5-hepten-2-one with
ethyl chloroacetate. The intermediate glycidate is saponified and decarboxylated
to yield the title compound.
It is used in many fragrance types and is invaluable in the creation ofmelon and
cucumber notes.
2,6-Dimethyl-5-heptenal has a characteristic odor of melon and a corresponding taste.
Reported found in lemon and lime peel oil, sudachi (Citrus sudachi H. ex. Shirai) and ginger.
It is used or fragrances designed to have a special fruity note tending towards melon, cucumber and pumpkin. It is mainly used perfuming agents.
By condensation of isobutyric aldehyde with α-methylcrotonaldehyde, followed by par tial hydrogenation; also from methylheptenone through Darzen's reaction.
Taste characteristics at 50 ppm: green, melon, watermelon-rind, cucumber, with a waxy, chemical and floral
nuance.
2,6-Dimethyl-5-heptenal (melonal) and 5-heptenal undergo concerted ene reaction to form zwitterion that further reacts to give ene product.
Flammability and Explosibility
Not classified
Melonal (Givaudan), Melomor (Aromor).
skin and eye irritant.
When heated to decomposition it emits
acrid smoke and irritating fumes.
