A process for preparing C.sub.4 to C.sub.13 monohydroxy compounds from a bottom fraction arising in the distillation of a crude mixture of C.sub.4 to C.sub.13 oxo-process aldehydes from cobalt-catalyzed or rhodium-catalyzed hydroformylation, or in the distillation of a crude mixture of C.sub.4 to C.sub.13 oxo-process alcohols, which comprises contacting the bottom fraction in the presence of hydrogen with a catalyst comprising copper oxide and aluminum oxide, at a temperature of 150° C. to 300° C. and a pressure of 20 bar to 300 bar and subjecting the resulting crude hydrogenation product to distillation, and the amount of C.sub.4 to C.sub.13 monohydroxy compounds present in the crude hydrogenation product after the hydrogenation being greater than the amount of C.sub.4 to C.sub.13 monohydroxy compounds given stoichiometrically from the hydrogenation of the ester and aldehyde compounds present in the bottom fraction, including the C.sub.4 to C.sub.13 monohydroxy compounds still present in the bottom fraction before the hydrogenation.

A process for preparing C.sub.4 to C.sub.13 monohydroxy compounds from a bottom fraction arising in the distillation of a crude mixture of C.sub.4 to C.sub.13 oxo-process aldehydes from cobalt-catalyzed or rhodium-catalyzed hydroformylation, or in the distillation of a crude mixture of C.sub.4 to C.sub.13 oxo-process alcohols, which comprises contacting the bottom fraction in the presence of hydrogen with a catalyst comprising copper oxide and aluminum oxide, at a temperature of 150° C. to 300° C. and a pressure of 20 bar to 300 bar and subjecting the resulting crude hydrogenation product to distillation, and the amount of C.sub.4 to C.sub.13 monohydroxy compounds present in the crude hydrogenation product after the hydrogenation being greater than the amount of C.sub.4 to C.sub.13 monohydroxy compounds given stoichiometrically from the hydrogenation of the ester and aldehyde compounds present in the bottom fraction, including the C.sub.4 to C.sub.13 monohydroxy compounds still present in the bottom fraction before the hydrogenation.

Processes are disclosed for the synthesis of a cracked product or an end product, from a starting compound or substrate having a carbonyl functional group (C═O), with hydroxy-substituted carbon atoms at alpha (α) and beta (β) positions, relative to the carbonyl functional group. According a particular embodiment, an α-, β-dihydroxy carboxylic acid or carboxylate is dehydrated to form a dicarbonyl intermediate by transformation of the α-hydroxy group to a second carbonyl group and removal of the β-hydroxy group. The dicarbonyl intermediate is cracked to form the cracked product, in which the first and second carbonyl groups are preserved. Either or both of (i) the cracked product and (ii) a second cracked product generated from cleavage of a carbon-carbon bond of the dicarbonyl intermediate, may be further converted (e.g., by hydrogenation) to one or more end products, which, like the cracked product(s), also having fewer carbon atoms relative to the dicarbonyl intermediate and substrate.

Processes are disclosed for the synthesis of a cracked product or an end product, from a starting compound or substrate having a carbonyl functional group (C═O), with hydroxy-substituted carbon atoms at alpha (α) and beta (β) positions, relative to the carbonyl functional group. According a particular embodiment, an α-, β-dihydroxy carboxylic acid or carboxylate is dehydrated to form a dicarbonyl intermediate by transformation of the α-hydroxy group to a second carbonyl group and removal of the β-hydroxy group. The dicarbonyl intermediate is cracked to form the cracked product, in which the first and second carbonyl groups are preserved. Either or both of (i) the cracked product and (ii) a second cracked product generated from cleavage of a carbon-carbon bond of the dicarbonyl intermediate, may be further converted (e.g., by hydrogenation) to one or more end products, which, like the cracked product(s), also having fewer carbon atoms relative to the dicarbonyl intermediate and substrate.

It has been discovered that mixed-alcohol production can utilize the waste tail gas stream from the pressure-swing adsorption section of an industrial hydrogen plant. Some variations provide a process for producing mixed alcohols, comprising: obtaining a tail-gas stream from a methane-to-syngas unit (e.g., a steam methane reforming reactor); compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; introducing the syngas stream into a mixed-alcohol reactor operated at effective alcohol synthesis conditions in the presence of an alcohol-synthesis catalyst, thereby generated mixed alcohols; and purifying the mixed alcohols to generate a mixed-alcohol product. Other variations provide a process for producing clean syngas, comprising: obtaining a tail-gas stream from a methane-to-syngas unit; compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; and recovering a clean syngas product.

It has been discovered that mixed-alcohol production can utilize the waste tail gas stream from the pressure-swing adsorption section of an industrial hydrogen plant. Some variations provide a process for producing mixed alcohols, comprising: obtaining a tail-gas stream from a methane-to-syngas unit (e.g., a steam methane reforming reactor); compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; introducing the syngas stream into a mixed-alcohol reactor operated at effective alcohol synthesis conditions in the presence of an alcohol-synthesis catalyst, thereby generated mixed alcohols; and purifying the mixed alcohols to generate a mixed-alcohol product. Other variations provide a process for producing clean syngas, comprising: obtaining a tail-gas stream from a methane-to-syngas unit; compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; and recovering a clean syngas product.

Continuous processes for making ethylene glycol form aldohexose-yielding carbohydrates are disclosed which enhance the selectivity to ethylene glycol.

Continuous processes for making ethylene glycol form aldohexose-yielding carbohydrates are disclosed which enhance the selectivity to ethylene glycol.

A method for preparing dimethylolbutanal including performing an aldol reaction of n-butyraldehyde (n-BAL) and paraformaldehyde (PFA) in the presence of water and an alkylamine catalyst, in which a weight ratio of the paraformaldehyde:water is 1:0.35 to 1:0.85.

The present disclosure is directed to methods of preparing prostaglandin J natural products by stereoretentive metatheses reactions and intermediates used in the synthesis of these natural products, including the use of intermediates of Formula (I-A), where R.sup.1 is defined in the specification ##STR00001##