Abstract: A compound represented by A-D-A is useful as a light. emitting material used in an organic electroluminescent device and others.

Abstract: A compound represented by A-D-A is useful as a light. emitting material used in an organic electroluminescent device and others.

Abstract: A novel process for preparing imidazopyran derivatives of the formula: wherein R1 is halogen atom, hydrogen atom, C1 to C3 alkyl group, aryl group, or aryl group substituted by C1 to C3 alkyl group, by using dinitroimidazole and 2,3-epoxy-1-propanol as starting materials and being followed by five steps.

Abstract: A novel process for preparing imidazopyran derivatives of the formula: wherein R1 is halogen atom, hydrogen atom, C1 to C3 alkyl group, aryl group, or aryl group substituted by C1 to C3 alkyl group, by using dinitroimidazole and 2,3-epoxy-1-propanol as starting materials and being followed by five steps.

Abstract: A process for preparing a biodegradable resin composition, comprising: providing a reaction mixture comprising at least one hydroxycarboxylic acid and, as a polymerization catalyst, a monoorganotin derivative; heating and stirring the reaction mixture, wherein the heating and stirring step is carried out under a reduced pressure to cause condensation polymerization or carried out in an organic solvent to cause azeotropic dehydrating polymerization. Also disclosed in a biodegradable resin composition prepared by the process.

Abstract: A process for preparation of a glycidyl ether which is characrelized in reacting an epoxy compound of the formula ##STR1## wherein X is halogen or sulfonyloxy in the presence of a fluoride salt, with an alcohol. According to the above method, glycigyl ethers or their optically active compounds important as intermediates for synthesis of medicines are easily obtained in good yield and especially the optically active compounds are obtained with highly optical purity.

Abstract: A process for preparation of 3-amino-2-hydroxy-1-propyl ether of the formula ##STR1## wherein R.sup.1 is substituted or unsubstituted alkyl, substituted or unsubstituted aryl, or substituted or unsubstituted heterocyclic ring, R.sup.2 and R.sup.3 are the same or different hydrogen atom, a substituted or unsubstituted alkyl, or may form a ring together with an adjacent nitrogen atom, which ring may be interrupted with nitrogen atom, oxygen atom or sulfur atom,which is characterized in reacting an epoxy compound of the formula ##STR2## wherein X is halogen, in the presence of a fluoride salt, with an alcohol and then reacting an amine.According to the above method, an intermediates for synthesis of medicines is obtained in good yield and highly optical purity.

Abstract: A process for the preparation of a readily hydrolyzable and/or biodegradable polyhydroxycarboxylic acid resin which can be used in agricultural materials, gardening materials, fishery materials, caking materials, medical instruments and materials, etc. and, even when discarded after use, which undergoes hydrolysis and/or is biodegraded into carbon dioxide, water, etc. Also disclosed are a hydrolyzable and/or biodegradable polyhydroxycarboxylic acid resin composition having an increased resin strength and melt viscosity, and a process for the preparation thereof.

Abstract: There is provided a method for easily preparing a polyhydroxycarboxylic acid resin in a one pot reaction by adding 1,3-substituted-1,1,3,3-tetraorganodistanoxan as a polymerization catalyst to a hydroxycarboxylic acid, such as L-lactic acid containing 10 to 50% of water as a starting material, and stirring while heating under a reduced pressure condition or in an organic solvent.

Abstract: A process for producing vitamin A represented by the formula ##STR1## which comprises treating a compound represented by the formula ##STR2## wherein R.sup.1 represents an aryl group which may be substituted, R.sup.21 and R.sup.22 each represent a hydrogen atom or a lower alkanoyl group, R.sup.3 represents an acetal-type protective group for a hydroxyl group, and X represents a halogen atom, with a base; and novel intermediate compounds useful for the above process.

Abstract: A process for producing vitamin A represented by the formula ##STR1## which comprises treating a compound represented by the formula ##STR2## wherein R.sup.1 represents an aryl group which may be substituted, R.sup.21 and R.sup.22 each represents a hydrogen atom or a lower alkanoyl group, R.sup.3 represents an acetal-type protective group for a hydroxyl group, and X represents a halogen atom, with a base; and novel intermediate compounds useful for the above process.

Abstract: A process for preparing .alpha.,.beta.-unsaturated aldehydes of the general formula (I) ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 are independently a hydrogen atom, or an alkyl or alkenyl group with or without being substituted with a lower acyloxy group. The aldehyde of the general formula (I) is prepared by reaction between an allylic chloride of the following general formula (IIa) ##STR2## in which R.sup.1, R.sup.2 and R.sup.3 have, respectively, the same meanings as defined above, and an amine oxide selected from the group consisting of tri(lower alkyl)amine N-oxides of the formula,R.sub.3.sup.4 N.sup.+ O.sup.-,in which R.sup.4 represents a lower alkyl group having from 2 to 4 carbon atoms, and N-lower alkylmorpholine N-oxides of the following formula ##STR3## in which R.sup.5 represents a lower alkyl group having from 1 to 4 carbon atoms. Alternatively, the aldehyde of the formula (I) is obtained by reaction between an allylic chloride of the following general formula (IIb) ##STR4## in which R.sup.

Abstract: Permanent magnet composites comprising a cured liquid polymer matrix and hard magnetic ferrite particles dispersed therein are disclosed. The magnetic ferrite particles are present in an amount within the range of from about 5 to about 14 parts per part of polymer matrix, the magnetic ferrite particles having a general formula MO.n Fe.sub.2 O.sub.3, wherein M is selected from the group consisting of barium, strontium, lead, and mixtures thereof, and n has a value in the range of from about 4.5 to about 6.2. Various additives may optionally be employed to improve compatibility of the matrix polymer with the ferrite particles and to improve processibility. Also disclosed is a method for producing such magnetic composites.