Chemical Properties
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.
Chemical Properties
2,6-Dimethyl-5-heptenal has a characteristic odor of melon and a corresponding taste.
Occurrence
Reported found in lemon and lime peel oil, sudachi (Citrus sudachi H. ex. Shirai) and ginger.
Uses
It is used or fragrances designed to have a special fruity note tending towards melon, cucumber and pumpkin. It is mainly used perfuming agents.
Preparation
By condensation of isobutyric aldehyde with α-methylcrotonaldehyde, followed by par tial hydrogenation; also from methylheptenone through Darzen's reaction.
Aroma threshold values
Detection: 16 ppb
Taste threshold values
Taste characteristics at 50 ppm: green, melon, watermelon-rind, cucumber, with a waxy, chemical and floral
nuance.
General Description
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
Trade name
Melonal (Givaudan), Melomor (Aromor).
Safety Profile
skin and eye irritant.
When heated to decomposition it emits
acrid smoke and irritating fumes.
