摘要:
(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.
摘要:
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.
摘要:
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.
摘要:
Disclosed is a 2-phenyl-2-(2'-piperidinylidene)acetate derivative suitably used for a raw material of a 2-phenyl-2-(2'-piperidinyl)acetate derivative and a process for manufacturing the same. Also disclosed is a process for manufacturing an optically active 2-phenyl-2-(2'-piperidinyl)acetate derivative which is a major intermediate for an antidepressant. The 2-phenyl-2-(2'-piperidinylidene)acetate derivative is manufactured by cyclizing a 7-(N-substituted amino)-3-oxo-2-heptanoate derivative. The optically active 2-phenyl-2-(2'-piperidinyl)acetate derivative is manufactured by asymmetrically hydrogenating the 2-phenyl-2-(2'-piperidinylidene)acetate derivative in the presence of a complex of a Group VIII transition metal or an acid.
摘要:
The present invention relates to a flavor composition or fragrance composition which can satisfy diversified requirements for flavored products, as well as to a flavor-improving agent which can improve the quality and release of aroma of a beverage or food. More particularly, the present invention relates to a flavor composition or fragrance composition which comprises an optically active S-alkyl 2-methylbutanethioate as an active ingredient, a flavor- or fragrance-added product, a flavor-improving agent which comprises an optically active S-alkyl 2-methylbutanethioate as an active ingredient, and a beverage or food having an improved flavor. The optically active S-alkyl 2-methylbutanethioate includes S-alkyl(R)-2-methylbutanethioate and S-alkyl(S)-2-methylbutanethioate.
摘要:
(A) a diacylated dopamine derivative represented by the formula (I): ##STR1## wherein R.sup.1 represents an alkyl group having 3 to 7 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, substituted or unsubstituted phenyl group or a substituted or unsubstituted nitrogen-containing heterocyclic group; and R.sup.2 represents a hydrogen atom or a lower alkyl group; or a salt thereof; and(B) one or more compounds selected from lactic acid esters, fatty acid monoglycerides and higher alcohols; optionally together with(C) an unsaturated fatty acid monohydric alcohol ester. This preparation has a sustained effect, a high skin permeability and a low skin irritativeness.
摘要:
The present invention relates to a flavor composition or fragrance composition which can satisfy diversified requirements for flavored products, as well as to a flavor-improving agent which can improve the quality and release of aroma of a beverage or food. More particularly, the present invention relates to a flavor composition or fragrance composition which comprises an optically active S-alkyl 2-methylbutanethioate as an active ingredient, a flavor- or fragrance-added product, a flavor-improving agent which comprises an optically active S-alkyl 2-methylbutanethioate as an active ingredient, and a beverage or food having an improved flavor. The optically active S-alkyl 2-methylbutanethioate includes S-alkyl(R)-2-methylbutanethioate and S-alkyl(S)-2-methylbutanethioate.
摘要:
A process for preparing an optically active (2S,3S)-allophenylnorstatin derivative (I) is disclosed, comprising asymmetrically hydrogenating a 4-phenyl-2-halogeno-3-oxobutyric ester (III) in the presence of a ruthenium-phosphine complex to obtain a 4-phenyl-(2S)-halogeno-(3R)-hydroxybutyric ester (IV), epoxidizing the ester (IV) in the presence of a base to obtain a 4-phenyl-(2S,3R)-epoxybutyric ester (V), reacting the ester (V) with a tri(lower alkyl)silylazide or a (lower alkyl)diarylsilylazide in the presence of a Lewis to obtain a (3S)-azido-4-phenyl-(2S)-trisubstituted silyloxybutyric ester (VI), hydrogenolyzing the ester (VI) into a (2S,3S)-allophenylnorstatin derivative (VII), protecting the amino group of the compound (VII), and, if desired, hydrolyzing the compound before or after the amino group protection. Compounds (I) can be obtained at high optical purity safely and in good yield.
摘要:
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.
摘要:
Compounds represented by the following general structural formula (1) and methods for producing the compounds: ##STR1## R.sup.1 represents a group such as benzyloxycarbonyl, R.sup.2 represents a lower alkyl group, R.sup.3 represents a hydrogen atom or a protecting group, each of M.sup.1 and M.sup.2 represents a metal atom, and n represents the atomic valence of M.sup.1. Intermediates for HMG-CoA reductase inhibitors can be prepared safely and easily from these compounds.