Abstract: Disclosed are novel active benzene derivatives represented by the general formula (I): ##STR1## (wherein X represents --COO--, --OCO--, --CH.sub.2 O-- or --OCH.sub.2 --; A represents a hydrogen atom, a halogen atom or an alkyl or alkoxyl group having 1 to 20 carbon atoms; R represents an alkyl group having 1 to 20 carbon atoms; l and m each represents a number of 1 or 2, n represents a number of 0 or 1, but when n is 0 the sum of l and m is 3 or less; and * indicates asymmetric carbon atom), a process for producing the same, liquid-crystalline substances containing said derivatives as active ingredient, and optical switching elements utilizing the liquid crystal compositions containing said liquid-crystalline substances.

Abstract: Disclosed in the present invention are the optically active aromatic compounds having a trifluoromethyl group useful as a component of ferroelectric liquid crystal compositions, a process for preparing the above compounds, liquid crystal compositions having the above compounds as an active ingredient, and liquid crystal elements using the above compositions. The optically active aromatic compounds of the Present invention represented by the formula: ##STR1## have the very excellent properties as a liquid crystal material and are useful for the preparation of liquid crystal compositions and the liquid crystal elements using such compositions.

Abstract: Acylaromatic compounds ##STR1## (Q: aromatic compound residue; R: straight, branched or cyclic aliphatic group, aromatic group or araliphatic group) are prepared in high yield by a reaction, in the presence of a boron trifluoride complex catalyst, of an aromatic compound with ##STR2## (X: H, Cl, Br; Y: Cl, Br) or with RCOOH in the presence of (XYCHCO).sub.2 O.

Abstract: Disclosed are herein optically active ester derivatives represented by the formula (I): ##STR1## (wherein R.sub.1 represents an alkyl group having 3 to 20 carbon atoms; R.sub.2 represents an optically active alkyl or alkoxyalkyl group having 3 to 15 carbon atoms optionally substituted by halogen atoms; Y represents --O--, --COO-- or --OCO--; X represents --COO-- or --OCO--; l represents a number of 1 or 2; k and m each represents a number of 0 or 1; n represents a number of 1 to 6), preparation processes therefor, liquid crystal materials containing such ester derivatives as active ingredient, and a light switching element using said liquid crystal materials as liquid crystal element.

Abstract: Disclosed are optically active aromatic carboxylic acid derivatives represented by the formula (I): ##STR1## (wherein R.sub.2 represents an alkoxyalkyl group having 1 to 20 carbon atoms or an alkyl group having 1 to 20 carbon atoms, which alkyl group may be substituted with a halogen atom; represents a number of 1 or 2; m represents a number of 0 or 1; and * indicates asymmetric carbon atom) and a process for producing such derivatives through the following reaction steps: ##STR2## The optically active aromatic carboxylic acid derivatives represented by the above-described formula (I) are useful as a liquid crystal material and can be also utilized as an intermeidate for the preparation of pharmaceuticals, agricultural chemicals and the like.

Abstract: Disclosed are herein optically active ether derivatives represented by the formula (I): ##STR1## (wherein X represents --COO-- or --OCO--; A represents an alkyl or alkoxyl group having 3 to 15 carbon atoms; R represents an alkyl or alkyloxyalkyl group having 1 to 20 carbon atoms; l and m each represents a number of 1 to 2; and * indicates an asymmetric carbon atom), preparation processes therefor, liquid crystal materials containing such ether derivatives as active ingredient, and an optical switching element using said liquid crystal materials as liquid crystal element.

Abstract: Disclosed are novel active benzene derivatives represented by the general formula (I): ##STR1## (wherein X represents --COO--, --OCO--, --CH.sub.2 O-- or --OCH.sub.2 --; A represents a hydrogen atom, a halogen atom or an alkyl or alkoxyl group having 1 to 20 carbon atoms; R represents an alkyl group having 1 to 20 carbon atoms; l and m each represents a number of 1 or 2, n represents a number of 0 or 1, but when n is 0 the sum of l and m is 3 or less; and * indicates asymmetric carbon atom), a process for producing the same, liquid-crystalline substances containing said derivatives as active ingredient, and optical switching elements utilizing the liquid crystal compositions containing said liquid-crystalline substances.

Abstract: A process for preparing an optically active cyclopentenone of the formula: ##STR1## wherein R is a hydrogen atom or a lower alkyl group and n is an integer of 4 to 8, which comprises contacting a dl-cyclopentenone ester of the formula: ##STR2## wherein R and n are each as defined above and R' is a lower alkyl group optionally substituted with halogen on an enzyme having a capability of hydrolyzing selectively either one of the d- or l-form isomer in the dl-cyclopentenone ester (II) in an aqueous medium for asymmetric hydrolysis.

Abstract: 2-Acylfuran derivatives ##STR1## (R: alkyl, phenyl, etc.; R.sub.1 : H, alkyl) are prepared in high yield by reaction, in the presence of a boron trifluoride complex catalyst, of a furan compound ##STR2## (X: H, Cl, Br; Y: Cl, Br) or with RCOOH in the presence of (XYCHCO).sub.2 O.