Kuraray Co., Ltd.

Masahiro Torihara

Yoshin Tamai

Junko Sato

Koichi Kanehira

Chikara Kaneko

Nobuya Katagiri

Tatsuhiko Hayashibara

Johji Yamahara

Yoichi Kido

Manzo Shiono

Takashi Fukumoto

Fumihiko Okabe

Yusuke Murata

Kensuke Nagashima

Eriko Matsuda

Kenji Tasaka

Masayoshi Ito

Eriko Fukumoto

The use of a metal complex containing a ruthenium ion or an osmium ion, and a tridentate aminodicarbene ligand, the tridentate aminodicarbene ligand having one secondary amino group and two specific heterocyclic carbene groups sandwiching the amino group, enables hydrogenation reduction of carbonyl compounds, such as ketones, carboxylic acid esters, lactones, carboxylic acid amides, and lactams, and imine compounds under relatively mild conditions to produce corresponding alcohols, amines, and the like in a high yield with high catalytic efficiency. The metal complex is obtained by a method comprising steps of reacting a specific metal compound with a specific aminodicarbene precursor and subsequently reacting a specific compound. Reduction of a carbonyl compound or an imine compound in the presence of this metal complex using a hydrogen donor makes it possible to reduce the carbonyl compound or imine compound by hydrogenation.

Metal complex including tridentate aminodicarbene ligand and hydrogenation reduction method using same

4-N-substituted amino-2-aza-1-oxabicyclo[3.3.0]oct-2-ene-6-carboxylic acid esters are produced by adding a Br&#xf8;nsted acid to a mixture of a 2-azabicyclo[2.2.1]hept-5-en-3-one and an alcohol, thereby causing these components to react with each other to give a salt of cis-4-amino-2-cyclopentene-1-carboxylic acid ester, then allowing the salt of cis-4-amino-2-cyclopentene-1-carboxylic acid ester thus obtained to react with an amino-protecting group introducing compound in the presence of a base, thereby giving cis-4-N-substituted amino-2-cyclopentene-1-carboxylic acid ester, and then allowing this cis-4-N-substituted amino-2-cyclopentene-1-carboxylic acid ester to react with a hypohalogenite and an aldoxime.

Process for preparation of 4-n-substituted amino-2-aza-1-oxabicyclo[3.3.0] oct-2-ene-6-carboxylic acid esters and process for preparation of their intermediates

A process for the preparation of 2-oxocarboxylic acid esters represented by the following general formula (I), comprising by oxidizing a 2-hydroxycarboxylic acid ester represented by the following general formula (II) in the presence of a nitroxyl radical represented by the following general formula (III), a hypochlorite, a metal bromide and water with the pH of the reaction system being kept within the range of 5 to 7:(I) (II) (III) wherein Rand Rare each independently an alkyl group, an alkenyl group, an alkynyl group, an aryl group or an aralkyl group, which each may be substituted with substituents; and Ris a hydrogen atom, an alkoxyl group, an aralkyloxy group, an acyloxy group or a hydroxyl group.

Process for preparation of 2-oxocarboxylic acid esters

A method for producing a chroman-carboxylic acid is provided, which method includes reacting a dialkylphenol compound, a formaldehyde and an alcohol in the presence of a secondary amine and an acid to give an alkoxymethylated phenol compound (Step 1); reacting the obtained alkoxymethylated phenol compound with an ester having a carbon-carbon double bond at a temperature of not less than 100&deg; C. to give a dialkylchroman carboxylic acid ester (Step 2); hydrolyzing the obtained dialkylchroman carboxylic acid ester to give a dialkylchroman-carboxylic acid (Step 3); and reacting the obtained dialkylchroman-carboxylic acid with an aromatic hydrocarbon in the presence of a Lewis acid (Step 4).

Method for producing chroman-carboxylic acid

Process for the preparation of benzyloxyacetaldehyde

A process for producing cyclopropanecarbonitrile involves reacting cyclopropanecarbaldoxime with acetic anhydride to obtain a mixture containing acetic acid and cyclopropanecarbonitrile. The acetic acid can be removed from the mixture through azeotropic distillation of acetic acid with a solvent that forms with acetic acid an azeotropic mixture having an azeotropic point lower than the boiling point of the cyclopropanecarbonitrile.

Process for producing cyclopropanecarbonitrile

Cyclopentenecarboxamide derivative, method for preparing the same and bicycloamide derivative used therein

Cyclopentenecarboxamide derivative, method for preparing the same bicycloamide derivative used therein

A cyclopentenecarboxamide derivative represented by the formula (I): ##STR1## and a method for preparing the cyclopentencarboxamide derivative. A bicycloamide derivative represented by the formula (II): ##STR2## and a method for preparing the bicycloamide derivative.

Cyclopentenecarboxamide derivative, method for preparing the same and

An optically active 5-methylenedioxolan-4-one derivative is subjected to Diels-Alder reaction with cyclopentadiene, and the resulting Diels-Alder reaction product is hydrolyzed to convert it into an optically active 2-hydroxynorbornene-2-carboxylic acid, which is then subjected to catalytic hydrogenation to form an optically active 2-hydroxynorbornane-2-carboxylic acid. The hydroxycarboxylic acid is subjected to oxidative decarboxylation to obtain an optically active 2-norbornanone.

Process for producing optically active 2-norbornanone

A phenol, a formaldehyde and an unsaturated compound having carbon-carbon double bond are reacted in the presence of a secondary amine and an acid at a temperature of 100.degree. to 250.degree. C., to give a chroman.

Process for producing chroman

The present invention provides conjugated .gamma.-hydroxybutenolide compounds represented by the general formula: ##STR1## wherein R represents, when n is 1, furyl groups, thienyl groups or naphthyl groups, unsubstituted or substituted with alkyl group or alkoxy group; phenyl groups substituted with dialkylamino group, acyl group or pyridinyl group; or ##STR2## when n is 2 or 3, phenyl groups unsubstituted or substituted with alkyl group or alkoxy group; and antiulcer agents comprising an aforementioned conjugated .gamma.-hydroxybutenolide compound as an active ingredient.

Conjugated .gamma.-hydroxybutenolide compounds and antiulcer agents

A skin depigmental agent characterized by comprising a resorcinol derivative having a linear alkyl group is provided.

Skin depigmental agent

A novel and useful method for treating and/or preventing ulcer in human beings is provided which comprises administering an effective amount of a pharmaceutical composition comprising at least one of the conjugated .gamma.-oxybutenolide compounds represented by the general formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are the same or different and represent hydrogen atoms, alkyl groups, hydroxyl groups, alkoxy groups, nitro groups, cyano groups or halogen atoms; and optionally at least one pharmaceutically acceptable carrier.

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Niigata, Japan

Masahiro Torihara