Takasago International Corporation

Takasago Perfumery Co., Ltd.

Tetsuo Ohta

Hidenori Kumobayashi

Hidemasa Takaya

Noboru Sayo

Susumu Akutagawa

Ryoji Noyori

Yoshiki Okeda

Takanao Taketomi

Yoshiharu Gonda

Nobuo Yamada

Toshiyuki Takezawa

Ryoli Noyori

A process for preparing optically active 4-methyl-2-oxetanone which comprises asymmetrically hydrogenating 4-methylene-2-oxetanone in the presence of a ruthenium-optically active phosphine complex. Optically active 4-methyl-2-oxetanone can easily and economically be obtained at high optical purity.

Process for preparing optically active 4-methyl-2-oxetanone

A process for producing an optically active carboxylic acid represented by formula (I): ##STR1## wherein R.sup.1, and R.sup.2, and R.sup.3 each represents a hydrogen atom, an alkyl group, an alkenyl group, or a phenyl or naphthyl group which may have a substituent, provided that all of R.sup.1, R.sup.2, and R.sup.3 are not simultaneously a hydrogen atom; when R.sup.1 and R.sup.2 are simultaneously a hydrogen atom, then R.sup.3 is not a methyl group; and that when R.sup.3 is a hydrogen atom, then R.sup.1 and R.sup.2 are each a group other then a hydrogen atom, is disclosed, comprising asymmetrically hydrogenating an .alpha.,.beta.-unsaturated carboxylic acid represented by formula (II): ##STR2## wherein R.sup.1, R.sup.2, and R.sup.3 are the same as defined above, in the presence of a ruthenium-optically active phosphine complex as a catalyst. According to the process of the invention, the desired optically active carboxylic acids which can be widely used as raw materials for synthesizing various useful compounds, for example, as intermediates for synthesizing physiologically active substances of natural materials and also as liquid crystal materials can be industrially advantageously produced.

Process for producing optically active carboxylic acid

A ruthenium-phosphine complex having a 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl or its derivative as a ligand and carboxyl groups bonded to the ruthenium atom thereof is disclosed. The complex is inexpensive and exhibits excellent performances as a catalyst for various organic syntheses, and particularly for asymmetric hydrogenation.

Ruthenium-phosphine complex

A ruthenium-phosphine complex represented by formula (I): [RuH.sub.l (R-BINAP).sub.m ]X.sub.n'            (I) wherein R-BINAP is a tertiary phosphine represented by formula (II): ##STR1## R is a hydrogen atom or a methyl group; X is a ClO.sub.4, BF.sub.4, or PF.sub.6 ; and when l is 0, then m is 1 and n' is 2, and when l is 1, then m is 2 and n' is 1, is disclosed. The complex is inexpensive and exhibits excellent performances as a catalyst for various organic syntheses, and particularly for asymmetric hydrogenation.

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Kyoto, Japan

Tetsuo Ohta