Unsaturated ketones of general formula (I) where the groups R1, R2, R3, R4 and R5 independently=H or 1-6 C alkyl groups, which can be saturated or unsaturated, straight-chained, branched or cyclic are characterised by an interesting and original odour characteristic with good emanation and are suitable for use as perfumes, for example in cosmetic preparations, technical products or alcoholic perfumery.