title: Optical Resolution by the Replacing Crystallization of DL-Threonine with L-Alanine as an Optically Active Cosolute.
abstract: DL-Threonine (DL-Thr) was optically resolved by replacing crystallization with L-alanine (L-Ala) as an optically active cosolute. D-Thr was preferentially crystallized from a supersaturated aqueous solution of DL-Thr in the presence of L-Ala. Optical resolution was successfully achieved to afford D-Thr with an optical purity of 96-98% and L-Thr of 91-95%. The partially resolved D- and L-Thr were recrystallized from water, taking account of the solubility of DL-Thr, to efficiently yield both enantiomers in an optically pure form.
authors.affiliation: a Chemical Branch, Faculty of Engineering and Kansai University High Technology Research Center, Kansai University.
authors.forename: T
authors.initials: T
authors.lastname: Shiraiwa
authors.affiliation: a Chemical Branch, Faculty of Engineering and Kansai University High Technology Research Center, Kansai University.
authors.forename: M
authors.initials: M
authors.lastname: Kubo
authors.affiliation: a Chemical Branch, Faculty of Engineering and Kansai University High Technology Research Center, Kansai University.
authors.forename: K
authors.initials: K
authors.lastname: Fukuda
authors.affiliation: a Chemical Branch, Faculty of Engineering and Kansai University High Technology Research Center, Kansai University.
authors.forename: H
authors.initials: H
authors.lastname: Kurokawa
keywords: L-alanine; optical resolution; replacing crystallization; threonine