5-メチル-2-ヘプテン-4-オン

化学的特性(2E)-5-Methyl-2-hepten-4-one has a fruity, hazelnut, and green odor reminding of dried fruits and a characteristic, nutty, roasted, and nougat-like hazelnut flavor. It was identified as the character compound of natural hazelnut flavor. Preparation is possible, for example, by Grignard reaction of 2-butyl magnesium chloride with crotonaldehyde and subsequent oxidation or by reaction of 2-methylbutanoyl chloride with propene. The material is used in fragrances as top-note booster in exotic fruit and citrus notes and in nut, cocoa, coffee, and so on, flavors.