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 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:
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:
Herein disclosed is a wireless electric appliance system, comprising an electric appliance having assigned thereto a control code, and a wireless remote control apparatus having assigned thereto an operation code to be matched with the control code. The electric appliance is operably connected with the electric appliance. The electric appliance includes storage means for storing therein the control code; and transmitting means for transmitting a signal including the control code stored in the storage means to the wireless remote control apparatus. The wireless remote control apparatus includes storage means for storing therein the operation code; receiving means for receiving the signal including the control code assigned to the electric appliance from the electric appliance; judging means for judging whether or not the operation code stored in the storage means is matched with the control code of the signal received by the receiving means, and control means for controlling the operation of the wireless remote control apparatus based on a result judged by the judging means.
摘要:
The present invention provides a novel 2-aralkyl-3-chloropropionic acid and a process for the preparation thereof. A novel 2-aralkyl-3-chloropropionic acid is represented by the general formula (1): ##STR1## and can be prepared by asymmetrically hydrogenating a (Z)-2-aralkylidene-3-chloropropionic acid represented by the general formula (II): ##STR2## with a complex of a bidentate phosphine with ruthenium as a catalyst in the presence of a tertiary amine.