A lactone compound is represented by general formula (A), and an ether compound is represented by general formula (B). In formula (A), R is a hydrogen atom or R1. When R is a hydrogen atom, R′ is R1, the carbon bond (1) is a single bond or a double bond, and the carbon bond (2) is a single bond. When R is R1, R′ is a hydrogen atom or R1, both the carbon bonds (1) and (2) are a single bond, or one of them is a double bond and the other is a single bond. In formula (B), R″ is R1. R1 represents a specific alkyl group, a specific alkenyl group, a specific alkynyl group, or an aryl group. In formulas (A) and (B), n is 0 or 1.