摘要:
The present invention is directed to a method for purifying pyruvic acid compounds, which method comprises reacting a pyruvic acid compound of general formula (I): wherein R1 is an optionally substituted lower alkyl group, a lower alkenyl group, a lower alkynyl group, a cycloalkyl group, an aryl group, or a heterocyclic group, and R2 is a lower alkyl group, with a bisulfite of general formula (II): MHSO3 (II) wherein M is NH4 or an alkali metal, to give a bisulfite adduct of the pyruvic acid compound and then decomposing the adduct with an acid. According to the present invention, pyruvic acid compounds can be purified by simple and easy procedures without using purification techniques such as distillation or column chromatography, and the above method is advantageous as a process for the production on an industrial scale.
摘要:
There is provided a process for producing N-substituted azetidine-.2-carboxylic acid of the formula I: ##STR1## wherein R.sup.1 denotes an aralkyl group or an arylated lower alkoxycarbonyl group and * designates an asymmetric carbon atom, which is characterized by:reacting an N-substituted azetidine-2-carboxylic acid ester of the formula II: ##STR2## wherein R.sup.1 has the same meaning as defined above and R.sup.2 denotes an alkyl group, an aralkyl group or an allyl group, with an enzyme capable of selectively hydrolyzing a stereoisomer based on the carbon atom of the 2-position of the azetidine ring.
摘要:
The present invention provides a process for preparing optically active azetidine-2-carboxylic acids using readily available reagents of relatively low price in the industry. Thus, there is provided optically active azetidine-2-carboxylic acid, and a process for producing the same by subjecting optically active N-(alkylbenzyl)azetidine-2-carboxylic acid represented by the formula (1): ##STR1## to hydrogenolysis in the presence of a catalyst.
摘要:
An optically active lysine alkyl ester.dihydrochloride is racemized by heating at 100.degree. C. to 250.degree. C. under an atmosphere of hydrogen. By combining this process with asymmetric hydrolysis of racemic lysine alkyl ester with enzymes, racemic lysine alkyl ester can be converted all to L-lysine.
摘要:
A novel optically active cis-4,5-disubstituted imidazolidin-2-one derivative of the formula: ##STR1## wherein R.sup.1 is a C.sub.1 -C.sub.4 alkyl group or benzyl and R.sup.2 is a chiral aralkyl group optionally having at least one of C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy and hydroxyl groups is produced asymmetrically by the reaction of 1,3-dibenzyl-cis-4,5-dicarboxy-imidazolidin-2-one or its anhydride with an optically active secondary amine of the formula: ##STR2## wherein R.sup.1 and R.sup.2 are each as defined above and is transformed into the lactone of 1,3-dibenzyl-cis-4-carboxy-5-hydroxymethyl-imidazolidin-2-one, which is a key intermediate in the synthesis of d-biotin.
摘要:
Enamides are prepared by hydrogenating oximes having at least one hydrogen atom at the .alpha.-position in the presence of a carboxylic anhydride using a ruthenium catalyst. These enamides are important to obtain amino group-containing compounds by reduction or polymerization.
摘要:
There is provided a process for producing an optically active N-substituted azetidine-2-carboxylic acid compound represented by the formula (2): ##STR1## by contacting a corresponding N-substituted azetidine-2-carboxylic acid ester of formula (2) with an enzyme derived from a microorganism selected from Arthrobacter SC-6-98-28 strain, Arthrobacter sp. ATCC21908 strain, Chromobacterium SC-YM-1 strain, and a mutant thereof. A process is also provided for preparing an optically active azetidine-2-carboxylic acid by eliminating the N-substituent of a N-substituted azetidine-2-carboxylic acid ester of formula (2).
摘要:
The present invention provides a process for preparing optically active azetidine-2-carboxylic acids using readily available reagents of relatively low price in the industry. Thus, there is provided optically active azetidine-2-carboxylic acid, and a process for producing the same by subjecting optically active N-(alkylbenzyl)azetidine-2-carboxylic acid represented by the formula (1): ##STR1## to hydrogenolysis in the presence of a catalyst.
摘要:
A method for producing a propargylamine compound represented by the general formula (I): ##STR1## which comprises reacting a propargyl compound represented by the general formula (II): ##STR2## with an aromatic aldehyde represented by the general formula (III): ArCHO (III) and ammonia to obtain an imine compound represented by the general formula (IV): ##STR3## and hydrolyzing the resultant imine compound. It is to provide a method for producing a propargylamine compound from a propargyl compound by a simple operation without using a special facility, using ammonia as a reaction reagent, without producing a dipropatygylamine compound and a tripropargylamine compound as by-products.
摘要:
A halogenated alkyl of the formula: ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different and each is a lower alkyl group, X is chlorine atom or a bromine atom and Y is a hydrogen atom or a halogen atom is prepared in high conversion and high selectivity by reacting a tertiary halogenated alkyl of the formula: ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and X are the same as defined above with an ethylene derivative of the formula:CH.sub.2 .dbd.CH--Y (III)wherein Y is the same as defined above in the presence of a liquid catalyst comprising aluminum chloride and an alkylbenzene of the formula: ##STR3## wherein R.sub.4, R.sub.5 and R.sub.6 are the same or different and each is a lower alkyl group or a hydrogen atom provided that at least one of them is a lower alkyl group.