To produce the subject compound in high yield by derivatizing an aminomethylbutanol and then separating the resultant derivative with an opticaly resolving column.

4-Amino-2-methylbutan-1-ol is derivatized by a method, e.g. a diaromatization such as dibenzoylation or dimononitrobenzoylation or diacylation such as diacetylation or dipropionylation and the resultant derivative is then separated by using an optical resolving column, e.g. the one prepared by supporting an optically active substance such as cellulose tris(3,5- dimethylphenylcarbamate) or amylose tris(phenylcarbamate) on a silica gel to produce the objective compound.