Abstract: Racemization of an optically active chrysanthemic acid derivatives of the formula: ##STR1## wherein X represents a chlorine atom, bromine atom or 2,2-dimethyl-3-isobutenyl-cyclopropane carboxyl group and * mark represents asymmetric carbon atom, is effected by contacting the acid derivatives with at least one compound selected from the group consisting of hydrogen bromide, a carboxylic acid bromide, an N-bromine compound, an S-bromine compound, a halobromine compound, a silicon-bromide compound, a phosphorus-bromide compound and an SH compound in the presence of a peroxide or an azo compound.

Abstract: Racemization of optically active chrysanthemic acid or its ester of the formula: ##STR1## wherein R represents a hydrogen atom or an alkyl, cycloalkyl or aralkyl group of 1-20 carbon atoms and * indicates an asymmetric carbon atom, is effected by contacting it with hydrogen bromide or a phosphorus bromide compound. This method may also be effected in the presence of a peroxide or an azo compound. This method is industrially very useful.

Abstract: A solid base with improved properties, such as excellent catalytic performance, is obtainable by reacting alumina with an alkali metal hydroxide in a reaction system at a temperature of 200.degree. to 500.degree. C. to form a reaction product; adding an alkali metal to the reaction system; and reacting the reaction product with the added alkali metal at a temperature of 180.degree. to 350.degree. C., or reacting water-containing alumina with an alkali metal in an amount of 1.01 to 2 times the molar equivalents of water contained in the water-containing alumina wherein a portion of the alkali metal of an amount not more than a molar equivalent of water contained in a reaction system at a temperature in a range between a melting point of the alkali metal and 500.degree. C. to form a reaction product and the reaction product is reacted with the rest of the alkali metal at a temperature of 180.degree. to 350.degree. C.

Abstract: 5-Ethylidene-2-norbornene with high quality is effectively prepared by isomerization 5-vinyl-2-norbornene containing 1 ppm to 0.5% by weight of 4-vinylcyclohexene in the presence of at least one catalyst selected from the group consisting of a solid base catalyst which is prepared by reacting alumina, an alkali metal hydroxide and an alkali metal in a temperature range of 200.degree. to 500.degree. C. and a solid base catalyst which is prepared by reacting water-containing alumina and an alkali metal in such an amount that exceeds a molar equivalent of water contained in alumina at a temperature in a range between a melting point of the alkali metal and 500.degree. C. in an inert gas atmosphere.

Abstract: Racemization of optically active, particularly the (-)-form of chrysanthemic acid or its ester of the formula: ##STR1## wherein R is, for example, hydrogen or an alkyl group, is effected by contacting it with boron tribromide or aluminum tribromide in the presence of an azo compound. This racemization procedure is useful from a commerical point of view.

Abstract: 5-Ethylidene-2-norbornene is effectively prepared by isomerization 5-vinyl-2-norbornene in the presence of at least one catalyst selected from a group consisting of a solid base catalyst which is prepared by reacting alumina and an alkali metal hydroxide at a temperature of 200.degree. to 500.degree. C. and then reacting the reaction produce with an alkali metal at a temperature of 180.degree. to 350.degree. C. and a solid base catalyst which is prepared by reacting water-containing alumina and an alkali metal in such an amount that corresponds to a molar equivalent of water contained in alumina at a temperature in a range between a melting point of the alkali metal and 500.degree. C. and then reacting the reaction product with an alkali metal at a temperature of 180.degree. to 350.degree. C.

Abstract: A solid base with improved properties, particularly excellent catalytic performance is prepared by reacting alumina and an alkali metal hydroxide at a temperature of from 200.degree. to 500.degree. C. and followed by reacting the resultant product with an alkali metal at a temperature of from 180.degree. to 350.degree. C. or reacting water-containing alumina and an alkali metal in such an amount that corresponds to a molar equivalent of water contained in alumina at a temperature in a range between a melting point of the alkali metal and 500.degree. C. and then reacting the reaction product with an alkali metal at a temperature of from 180.degree. to 350.degree. C.

Abstract: An optically active chrysanthemic acid or esters thereof are conveniently racemized with an aluminum bromide compound such as aluminum tribromide. An organic hydroperoxide should always be added to for racemization of the esters, but is not always necessary for racemization of the acid.

Abstract: The present invention relates to a method for racemization of a chrysanthemic acid or its ester, which comprises contacting the acid or its ester with a boron bromide compound, optionally in the presence of organic hydroperoxide.

Abstract: A novel substituted diene alcohol represented by a general formula: ##STR1## wherein X represents a group of the formula ##STR2## and a process for the preparation thereof a lower alkoxycarbonyl group of a substituted diene carboxylic acid ester having an E configuration obtained by the treatment of a chrysanthemic acid ester with Bronsted acid or a substituted diene carboxylic acid ester having a Z configuration obtained by the thermal cleavage of a chrysanthemic acid ester is reduced to methylol derivative.

Abstract: The present invention is to provide the process for preparing racemized cyclopropanecarboxylic acids or their acid anhydrides from the corresponding optically active, particularly levo-rotatory, cyclopropanecarboxylic acid anhydrides. The racemization is effected by the treatment of the optically active acid anhydride with a Lewis acid. Thus, the present racemization process enables more efficient commercial production of dextro-rotatory cyclopropanecarboxylic acids, which are the more effective acid component of pyrethroidal insecticides, when combined with an optical resolution process.

Abstract: A process for isomerization of cis-chrysanthemate esters by contacting a chrysanthemate ester containing a cis-chrysanthemate ester with a Lewis acid, to transform the cis-chrysanthemate ester into trans-chrysanthemate ester through epimerization at C.sub.3 -position. The starting cis-chrysanthemate ester may be of any optical isomer ratio form (+)-form to (-)-form, including racemic form. Accordingly the process is effectively employable for the preparation of a (+)-trans-chrysanthemate ester from the (+)-cis-chrysanthemate ester. Combinations of the process with optical resolution would make the commercial production of (+)-trans-chrysanthemic acid more effective, the latter being an important acid component of pyrethroidal insecticides.

Abstract: A method for racemization of optically active 2,2-dimethylcyclopropane-1-carboxylic acid by converting said acid to the corresponding halide thereof represented by the general formula; ##STR1## wherein X is a halogen atom, which is heated to a temperature of about 80.degree. C. to about 300.degree. C., preferably about 100.degree. C. to about 200.degree. C., and then, if desired, producing 2,2-dimethylcyclopropane-1-carboxylic acid by hydrolysis of the resultant acid halide.

Abstract: A novel substituted diene alcohol represented by a general formula: ##STR1## wherein X represents a group of the formula ##STR2## and a process for the preparation thereof wherein a lower alkoxycarbonyl group of a substituted diene carboxylic acid ester having an E configuration obtained by the treatment of a chrysanthemic acid ester with Bronsted acid or a substituted diene carboxylic acid ester having a Z configuration obtained by the thermal cleavage of a chrysanthemic acid ester is reduced to methylol derivative.

Abstract: A process for preparing trans-chrysanthemic acid which comprises reacting a mixture of alkyl trans-chrysanthemate and alkyl cis-chrysanthemate with an equimolar amount or less of an alkali with respect to the trans-isomer in the presence of water or an alcohol to hydrolyze the trans-isomer predominantly and separating the hydrolyzed trans-isomer from the unreacted cis-isomer.

Abstract: Alkyl cis-chrysanthemate is treated with a catalytic amount of alkali metal alkoxide at a temperature of about 50.degree. to 200.degree.C in the absence or presence of an aprotic solvent to give alkyl trans-chrysanthemate in a high purity and an excellent yield.