Methods for the preparation of alkenes including insect pheromones are described. The methods include homologation reactions employing reagents such as 1,3-diesters, epoxides, cyanoacetates, and cyanide salts for elongation of starting materials and intermediates by one or two carbon atoms. The alkenes include insect pheromones useful in a number of agricultural applications.

Methods for the preparation of alkenes including insect pheromones are described. The methods include homologation reactions employing reagents such as 1,3-diesters, epoxides, cyanoacetates, and cyanide salts for elongation of starting materials and intermediates by one or two carbon atoms. The alkenes include insect pheromones useful in a number of agricultural applications.

A composition containing a polyphenol compound (B), wherein the polyphenol compound (B) is one or more selected from the group consisting of a compound represented by the following formula (1) and a resin having a structure represented by the following formula (2):

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A method of manufacturing a cetane-boosting fuel additive includes reacting formaldehyde and 2-ethylhexanol at a mole ratio of 10:1 to 1:1, or 5:1 to 1.5:1, or 4:1 to 2:1, or 3.5:1 to 2.5:1 in the presence of a heterogeneous acid catalyst at a temperature of 300 to 375 K to obtain a cetane-boosting product mixture comprising H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOH, H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOCH.sub.2CH(CH.sub.2CH.sub.3)(CH.sub.2).sub.3CH.sub.3, or a combination thereof, wherein n has an average value of 2.8 to 3.2, preferably an average value of 3.

A method of manufacturing a cetane-boosting fuel additive includes reacting formaldehyde and 2-ethylhexanol at a mole ratio of 10:1 to 1:1, or 5:1 to 1.5:1, or 4:1 to 2:1, or 3.5:1 to 2.5:1 in the presence of a heterogeneous acid catalyst at a temperature of 300 to 375 K to obtain a cetane-boosting product mixture comprising H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOH, H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOCH.sub.2CH(CH.sub.2CH.sub.3)(CH.sub.2).sub.3CH.sub.3, or a combination thereof, wherein n has an average value of 2.8 to 3.2, preferably an average value of 3.

The disclosure relates to a process for continuously producing polyoxymethylene dimethyl ethers at low temperature, pertains to the technical field of polyoxymethylene dimethyl ether preparation processes, and solves the technical problem of continuous production of polyoxymethylene dimethyl ether. A membrane separation element with precisely controlled pores in membrane is used to realize a direct separation of the feedstocks from the catalyst within the reactor, and effectively reduce the permeation resistance of the separation membrane tube. By oppositely switching the flowing direction of liquid reaction materials, the adhesion of the catalyst to the separation membrane tube is inhibited, and some particles stuck in separation membrane tube are removed, which ensures the continuous operation of the reaction process and allows a molecular sieve catalyst to exhibit its advantage of long catalytic life.

The disclosure relates to a process for continuously producing polyoxymethylene dimethyl ethers at low temperature, pertains to the technical field of polyoxymethylene dimethyl ether preparation processes, and solves the technical problem of continuous production of polyoxymethylene dimethyl ether. A membrane separation element with precisely controlled pores in membrane is used to realize a direct separation of the feedstocks from the catalyst within the reactor, and effectively reduce the permeation resistance of the separation membrane tube. By oppositely switching the flowing direction of liquid reaction materials, the adhesion of the catalyst to the separation membrane tube is inhibited, and some particles stuck in separation membrane tube are removed, which ensures the continuous operation of the reaction process and allows a molecular sieve catalyst to exhibit its advantage of long catalytic life.

A method of manufacturing a cetane-boosting fuel additive includes reacting formaldehyde and 2-ethylhexanol at a mole ratio of 10:1 to 1:1, or 5:1 to 1.5:1, or 4:1 to 2:1, or 3.5:1 to 2.5:1 in the presence of a heterogeneous acid catalyst at a temperature of 300 to 375 K to obtain a cetane-boosting product mixture comprising H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOH, H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOCH.sub.2CH(CH.sub.2CH.sub.3)(CH.sub.2).sub.3CH.sub.3, or a combination thereof, wherein n has an average value of 2.8 to 3.2, preferably an average value of 3.

A method of manufacturing a cetane-boosting fuel additive includes reacting formaldehyde and 2-ethylhexanol at a mole ratio of 10:1 to 1:1, or 5:1 to 1.5:1, or 4:1 to 2:1, or 3.5:1 to 2.5:1 in the presence of a heterogeneous acid catalyst at a temperature of 300 to 375 K to obtain a cetane-boosting product mixture comprising H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOH, H.sub.3C(CH.sub.2).sub.3CH(CH.sub.2CH.sub.3)CH.sub.2(OCH.sub.2).sub.nOCH.sub.2CH(CH.sub.2CH.sub.3)(CH.sub.2).sub.3CH.sub.3, or a combination thereof, wherein n has an average value of 2.8 to 3.2, preferably an average value of 3.

The present disclosure relates to a composition that includes a compound having the structure R.sub.1O(CH.sub.2O).sub.nR.sub.2 and a cetane number between about 65 and about 100, where n is between 1 and 10, inclusively, R.sub.1 includes a first alkyl group, and R.sub.2 includes a second alkyl group.