This invention offers 6,8,10-undecatrien-3-one or 6,8,10-undecatrien-4-one which are represented by the following formula (1)[in the formula, either one of A and B stands for carbonyl group and the other stands for methylene group, and the wavy line signifies cis-form, trans-form, or a mixture of cis- and trans-form at an optional ratio]and which can reproduce an odor rich in naturality and freshness.
