Raspberry ketone is a natural phenolic compound that is the primary aroma compound of red raspberries. It is used in perfumery, in cosmetics, and as a food additive to impart a fruity odor. It is one of the most expensive natural flavor components used in the food industry. The natural compound can cost as much as $20,000 per kg. In 1965, the Food and Drug Administration placed raspberry ketone on generally recognized as safe (GRAS) status.
Since the natural abundance of raspberry ketone is very low, it is prepared industrially by a variety of methods from chemical intermediates. One of the ways this can be done is through a crossed aldol-catalytic hydrogenation. In acetone and sodium hydroxide, 4-hydroxybenzaldehyde can form the α,β-unsaturated ketone. This then goes through catalytic hydrogenation to produce raspberry ketone. This method produces a 99% yield.
When given to mice in high doses (up to 2% of food intake), raspberry ketone has been shown to prevent high-fat-diet-induced elevations in body weight. This effect is reported to stem from the alteration of lipid metabolism, increasing norepinephrine-induced lipolysis. Although products containing this compound are marketed for weight loss, this effect has not been studied in humans.