Takasago International Corporation

Noboru Sano

Hidenori Kumobayashi

Noboru Sayo

Tetsuro Yamasaki

Toshiyuki Murayama

Takero Ishizaki

Yoshifumi Yuasa

Masao Konno

A process for preparing optically active 3-hydroxy-.gamma.-butyrolactone or optically active 3-hydroxytetrahydrofuran through a short route and by using an easily available and inexpensive starting material and an inexpensive reagent easy to handle is disclosed. The process comprises cyclizing an optically active compound represented by formula (II): ##STR1## wherein Q represents an alkoxycarbonyl group having 1 to 4 carbon atoms or a hydroxymethyl group; X represents a halogen atom; and the asterisk * means an asymmetric carbon atom, under an acidic condition.

Process for preparing optically active cyclic compounds

Disclosed herein is a process for producing a (2S,5S)-2,5-diamino-1,6-diphenyl-3-hexanone derivative represented by the formula (1): ##STR1## wherein R.sup.1 means a lower alkylcarbonyl group, a halogen-substituted lower alkylcarbonyl group, an arylcarbonyl group or a lower alkoxycarbonyl group, and R.sup.2 and R.sup.3 are identical with or different from each other and denote individually an aryl group or an alkoxy-substituted aryl group, which comprises subjecting a (2S)-2,5-diamino-1,6-diphenyl-4-hexen-3-one derivative represented by the formula (2): ##STR2## wherein R.sup.1, R.sup.2 and R.sup.3 have the same meaning as defined above, to a hydrogenation reaction in the presence of a transition metal-containing catalyst.

Process for producing optically active diaminohexanone derivative

A process for for producing a (2R,3S)-cyclohexylnorstatine or a salt thereof is disclosed, which comprises the steps of: enantioselectively hydrogenating a 4-cyclohexyl-2-halogeno-3-oxobutyric acid ester in the presence of a ruthenium-phosphine complex to produce a 4-cyclohexyl-2-halogeno-(3R)-hydroxybutyric acid ester (2); epoxidizing the compound (2) in the presence of a base to produce a 4-cyclohexyl-(2S,3R)-epoxybutyric acid ester (3); reacting the compound (3) with a lower trialkylsilyl azide in the presence of a Lewis acid to produce a (3S)-azide-4-cyclohexyl-(2S)-substituted butyric acid ester (4); subjecting the compound (4) to hydrogenolysis to produce a (2S,3S)-cyclohexylnorstatine derivative (5); and inverting the configuration at the 2-position of the compound (5).

Process for producing cyclohexylbutyric acid derivative

A process for producing an optically active 1-substituted-1,3-propanediol is disclosed, comprising hydrogenating a 3-substituted-3-oxopropanol or 3-substituted-3-oxopropanal in the presence of a ruthenium-phosphine complex represented by formula (I):

Process for producing optically active 1-substituted-1,3-propanediols

A ruthenium-phosphine complex is disclosed, represented by formula (I):

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Kanagawa, Japan

Noboru Sano