The present invention provides a method for industrially producing an
optically active lysine derivative useful as a pharmaceutical
intermediate. More particularly, the present invention provides a
production method including protecting an amino group or an amino group
and carboxyl group of optically active 2-amino-6-methyl-6-nitroheptanoic
acid with a protecting group, reducing a nitro group to synthesize a
6,6-dimethyl lysine derivative and reacting the 6,6-dimethyl lysine
derivative with an acetic acid derivative.