Abstract: The present invention provides a method for separating a compound represented by Formula (1) or (2) [in the formula, P1 is a hydrogen atom or a protective group of a hydroxyl group, R1 is a linear or branched C1-6 alkyl group that may be substituted with a phenyl group, A is an alkenylene group, and R2 is a hydroxyl group, a C1-3 alkoxy group, a mono(C1-3 alkyl)amino group, or a di(C1-3 alkyl)amino group] from a geometrical isomer thereof, in which the geometrical isomer is a geometrical isomer in a double bond included in A, the method including processing a mixture containing the compound and the geometrical isomer thereof by a chromatographic method using an acidic functional group-modified silica gel as a stationary phase.