Takasago International Corporation

Daiichi Pharmaceutical Co., Ltd.

Akio Tachikawa

Yoshifumi Yuasa

Yoshiki Okeda

Shunichi Harada

Hidenori Kumobayashi

Toshimitsu Hagiwara

Shinya Yamada

Tsukasa Sotoguchi

Haruki Tsuruta

Toyohiko Kobayashi

Toshihiro Fujiwara

Hiroyuki Kenmochi

Teruyoshi Akiyama

Akira Nagakura

Kouji Ishiguro

A process for producing a pivaloylacetic acid ester comprises reacting pivaloyl chloride with an acetoacetic acid ester of an alkyl group having 1 to 4 carbon atoms in the presence of at least one nitrogen-containing basic compound (a) selected from among pyridine compounds, N,N-dialkylanilines and imidazole compounds and from 0.01 to 0.5 mole equivalent, based on the pivaloyl chloride, of a magnesium compound (b) to thereby prepare a pivaloylacetoacetic acid ester and then alcholyzing or alkali-hydrolyzing the pivaloylacetoacetic acid ester to thereby give a pivaloylacetic acid ester having a high purity at a low cost.

Process for producing pivaloyl-acetic acid ester

To offer a method of producing useful para-menthane-3,8-diol having the excellent repellent action to harmful living things, including noxious insects, in high purity and high yield, simply, and economically by the use of citronellal as a raw material compound. The above-mentioned problems are resolved by the production method of this invention wherein citronellal is treated with aqueous sulfuric acid solution of 0.02 to 1.0 wt. % in concentration to produce para-menthane-3,8-diol. In case of recovering the produced para-menthane-3,8-diol, a method is preferably adopted, wherein after the reaction product is extracted with an aliphatic hydrocarbon solvent of 5 to 8 in carbon number, the extract is cooled down at temperature higher than the melting point of said aliphatic hydrocarbon solvent and of -10.degree. C. or less to crystallize para-menthane-3,8-diol.

Method for producing para-menthane-3,8-diol

A novel process for producing 3-oxocarboxylic acid esters, which are useful as intermediates in the synthesis of ceramides to be used as a humectant, biodegradable polymers, drugs, etc., at a high purity and a high yield without requiring any troublesome procedure, is disclosed. The process comprises reacting an acetoacetic ester with a calcium compound, a barium compound or a strontium compound in the presence of an organic solvent at a temperature of 10 to 120.degree. C., further reacting the obtained product with a carboxylic acid chloride to thereby acylate it, and then adding thereto an alcohol in an amount 1 to 5 times by mol as much as the calcium compound, barium compound or strontium compound to thereby deacetylate the same.

Process for producing 3-oxocarboxylic acid esters

(2R,3R)-3-N-(L-aspartyl)amino-1-(1-methyl-2-norbornyl)-2-butanol and (2R,3R)-3-N-(L-aspartyl)amino-1-(3-methyl-2-norbornyl)-2-butanol as well as a sweetener comprising the same are disclosed. These compounds, which have excellent sweetness characteristics and are stable in acidic aqueous solutions, are highly useful as a sweetener in various fields.

N-(l-aspartyl)amino alcohol derivative and sweetener containing the same

A process for production of an optically active isomer of 2-(tetrahydropyran-2-yloxy)-1-propanol represented by formula (I): ##STR1## is disclosed, which comprises reacting an optically active isomer of a 1-acyloxy-2-propanol represented by formula (II): ##STR2## wherein R is a substituted or unsubstituted aryl group, with 3,4-dihydro-2H-pyran to obtain an optically active isomer of a 1-acyloxy-2-(tetrahydropyran-2-yloxy)propane represented by formula (III): ##STR3## wherein R is as defined above, and hydrolyzing the compound (III) to eliminate the acyl group. The optically active isomer of 2-(tetrahydropyran-2-yloxy)-1-propanol represented by formula (I) is an intermediate for synthesis of pyridobenzoxazine derivatives useful as a synthetic antibacterial agent, particularly an optically active isomer of ofloxacin.

Process for production of optically active

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Kanagawa, Japan

Akio Tachikawa