Abstract: The present invention relates to a Cu-based catalyst, a preparation process thereof and its use as the dehydrogenation catalyst in producing a hydroxyketone compound such as acetoin. Said Cu-based catalyst contains copper, at least one auxiliary metal selected from metal of Group IIA, non-noble metal of Group VIII, metal of Group VIB, metal of Group VIIB, metal of Group IIB and lanthanide metal of periodic table of elements, and an alkali metal, and further contains at least one ketone additive selected from a ketone represented by formula (II) and a ketone represented by formula (II?). Said Cu-based catalyst shows a high the acetoin selectivity as the dehydrogenation catalyst for producing acetoin. R1-C(?O)—CH(OH)—R2??(II) R1-C(?O)—CH(?O)—R2??(II?) In formulae (II) and (II?), each group is defined as in the description.

Abstract: After an aqueous solution containing, at a concentration of less than 40% by mass, an organic compound having two or more hydrophilic groups in a molecule is adjusted to contain the organic compound at a concentration of equal to or greater than 40% by mass, the aqueous solution whose organic compound concentration is adjusted to equal to or greater than 40% by mass is irradiated with an ultrasonic wave to atomize water, and is dehydrated and concentrated.

Abstract: There is provided a process for the preparation of a polymerizable composition comprising a cross-linker and a polymerizable monomer of formula (I) comprising (i) contacting a compound of formula (II) with an acid such as an imobilized acid; and (ii) neutralizing product of (i) such that a crosslinker is formed.

Abstract: Delayed release flavorant compositions containing flavor-release additives, namely 1,2-diols of the formula wherein R1 is one of the radicals where R2 is H, lower alkyl R3, R4 are H, lower alkyl, lower alkoxy, hydroxy, or R3+R4 together are methylenedioxy, R5 is lower alkyl and the broken lines represent in the ring one additional bond and in the side chain an optional bond.

Abstract: This invention relates to an improved process for the dehydration of 2,5-dimethyl-2,5-hexanediol to give good yields of 2,5-dimethyl-2,4-hexadiene with a minimum of by-products. This is accomplished by heating 2,5-dimethyl-2,5-hexanediol with a montmorillonite clay catalyst, preferably in the presence of a lower aliphatic alcohol.

Abstract: 2,5-Dimethyl-2,4-hexadiene is prepared by dehydrating 2,5-dimethyl-2,5-hexanediol in liquid phase. The reaction takes place by contacting 2,5-dimethyl-2,5-hexanediol, melted or dissolved in an appropriate solvent, with acids, heating the mixture at a temperature of 100.degree. C.-160.degree. C. and distilling off water from the reaction environment as it is being formed. The pressure can range between 1 and 10 bars.

Abstract: A process for producing isoprene, which comprises decomposing a mixture of at least two compounds represented by the general formula ##STR1## wherein (i) W and Y each represent a hydrogen atom, and X and Z are identical or different and each represent the group OR, (ii) W and X together form a single bond, Y represents a hydrogen atom and Z represents the group OR, (iii) W represents a hydrogen atom, X and Y together form a single bond, and Z represents the group OR, or (iv) W represents a hydrogen atom, X represents the group OR, and Y and Z together form a single bond, in which R represents a hydrogen atom, a methyl group, a methoxymethyl group, a methylbutenyl group, a methylbutenyloxymethyl group, a 1,1-dimethyl-3-hydroxypropyl group, a 1,1-dimethyl-3-hydroxypropyloxymethyl group, a 3-methyl-3-hydroxybutyl group, a 3-methyl-3-hydroxybutyloxymethyl group, a 1,1-dimethyl-3-methoxypropyl group, a 1,1-dimethyl-3-methoxypropyloxymethyl group, a 3-methyl-3-methoxybutyl group or a 3-methyl-3-methoxybutyloxymethy

Abstract: A process for producing a conjugated diene represented by the general formula ##STR1## wherein R.sub.3, R.sub.4 and R.sub.5 each represent a hydrogen atom, or any one of them represents a methyl group and the other two each represent a hydrogen atom,which comprises heating an alkane-1,3-diol represented by the general formula ##STR2## wherein R.sub.1 and R.sub.2 each represent a hydrogen atom, or one of them represents a hydrogen atom and the other represents a methyl group,to a temperature of at least 130.degree. C. in the liquid phase in the presence of water and a boron-oxyacid or an oxygen-containing boron compound capable of forming a boron-oxyacid it under the reaction conditions.