Takasago International Corporation

Takero Ishizaki

Noboru Sayo

Hidenori Kumobayashi

Takao Saito

Tetsuro Yamasaki

Toshiyuki Murayama

Tohru Yokozawa

Noboru Sano

Tetsuo Nakatsu

Carter B Green

Andrew T Lupo

A cooling sensate compound having the general formula (I):where n is an integer from 2 to 6. The compound is effective in imparting a refreshing and cooling sensation of long duration. A cooling sensate composition having the general formula (I) is used in a variety of formulations to impart the refreshing and cooling sensation. These cooling sensates are useful in a variety of consumer products including mouth formulations, food products and toiletries.

(1R, 2S, 5R)-3-1-menthoxyalkan-1-OL cooling sensate

A process for producing a diphosphine oxide or diphosphonate represented by formula (1) as defined, which comprises treating, with a base, a phosphine compound represented by formula (2) as defined and adding the thus-treated phosphine compound to a nonpolar solvent having an oxidative metal compound suspended therein so as to effect dimerization. The present invention makes it possible to produce, conveniently, in a high yield and safely, a diphosphine oxide or diphosphonate which is an intermediate for producing a diphosphine compound useful as a ligand of a metal complex serving as a catalyst for asymmetric synthesis reaction.

Production process of diphosphine oxide and diphosphonate

This invention provides a novel diphosphine compound which is useful as a ligand of catalysts for asymmetric synthesis reactions, particularly asymmetric hydrogenation reaction. Particularly, it provides a diphosphine compound represented by a general formula (1):

Optically active diphosphine compound, production intermediate thereof, transition metal complex containing the compound as ligand and asymmetric hydrogenation catalyst containing the complex

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

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Shizuoka, Japan

Takero Ishizaki