Branched-chain alcohols production

Boron enolates can be obtained from esters40,41 and amides42 by methods that are similar to those used for ketones. Various combinations of borylating reagents and amines have been used and the E.Z ratios are dependent on the reagents and conditions. In most cases esters give Z-enolates, which lead to syn adducts, but there are exceptions. Use of branched-chain alcohols increases the amount of anti enolate, and with t-butyl esters the product ratio is higher than 97 3. 

Secondary alcohols are much different chemically than primary alcohols, such as natural alcohols. In addition, commercial secondary alcohols are prepared from both even and odd carbon-numbered n-paraffins and thus contain both even and odd carbon-numbered alcohols. Oxo alcohols are primary alcohols, as are natural alcohols. However, oxo alcohols contain from twenty to sixty percent branched chain alcohols and also contain both even and odd carbon-numbered homologs. Ziegler alcohols are very similar to natural alcohols. They are primary alcohols and are a mixture of only even carbon-numbered homologs. The major differences between Ziegler and natural alcohols are trace impurities present and the range of synthetic products, C -C30, available. 

The product of photplysis of thebainequinol, previously reported to be a dimer,has been shown by X-ray studies to have the structure (131). Branched chain alcohols in the 6,14-endo-ethanotetrahydrothebaine series of structure (132 R = Me or H) are readily rearranged by formic acid to tetra-hydrofurans (133), which are further transformed by mineral acid into the bases (134) with the loss of the elements of water.These acid-catalysed rearrangements differ markedly from those previously reported for unbranched alcohols. ... 

Ester formation is associated with yeast growth in the early phase of fermentation. Acetate esters are produced via the reaction between an alcohol and acetyl Co-A, which is catalysed by the enzyme alcohol acetyl transferases (ATFl and ATF2). Ethanol, branched-chain alcohols and 2-phenylethanol are the common moieties of acetate esters. Ethyl esters of medium-chain fatty adds are formed through the reaction between ethanol and respective fatty acyl Co-A, which is catalysed by the enzyme alcohol acyl transferases. Saccharomyces cerevisiae strains also produce esterases that hydrolyse esters, and thus the final concentration of esters in beers is the net balance between ester synthesis and hydrolysis. Strains of brewing yeasts produce predominantly ethyl esters of fatty acids, particularly ethyl octanoate, with relatively little formation of acetate esters. Ester production in beer is regulated by a number of factors such as yeast strain, temperature, hydrostatic pressure, wort composition, sugar type and concentration, type and amount of yeast-assimilable nitrogen, aeration, and unsaturated fatty acids (Hiralal, Olaniran, PiUay, 2014 Pires et al., 2014). 

The Access Code for the Microbial Production of Branched-Chain Alcohols 2-Ketoacid Decarboxylase and an Alcohol Dehydrogenase... 

THE ACCESS CODE FOR THE MICROBIAL PRODUCTION OF BRANCHED-CHAIN ALCOHOLS... 

Lu J, Brigham CJ, Gai CS, Sinskey AJ. (2012). Studies on the production of branched-chain alcohols in engineered Ralstonia eutropha. Appl Microbiol Biotechnol, 96, 283-297. 

Sugars Unusual sugars (amino, deoxy and methyl sugars, and sugars with branched chains). Reduction products (sugar alcohols, cyclitols, streptidine). Oxidation products (uronic acids, aldonic acids, sugar dicarboxylic acids). 

Avalos, J.L., Fink, G.R., and Stephanopoulos, G. (2013) Compart-mentalization of metabolic pathways in yeast mitochondria improves the production of branched-chain alcohols. Nat. Biotechnol, 31, 335-341. 

Branched-chain alcohols were used extensively for surfactant manufacture prior to the changeover to the more readily biodegradable hnear products. They were usually derived from polypropylenes by the oxo process, which involves catalytic addition of carbon monoxide and hydrogen to the double bond in a sequence of reactions. Thus the tetrapropylene derivative is nominally a C13 alcohol, as highly branched as the original raw material. 

This second reaction leads to the small amount of branching (usually less than 5%) observed in the alcohol product. The alpha olefins produced by the first reaction represent a loss unless recovered (8). Additionally, ethylene polymerisation during chain growth creates significant fouling problems which must be addressed in the design and operation of commercial production faciUties (9). 

These are two chemically different groups of products which have distinct application fields. Both product groups are obtained by reacting maleic acid anhydride (MA) with hydroxyl group(s)-carrying molecules, followed by sulfation of the intermediate product, an ester. Whereas the diester types are mainly made from a few different branched and unbranched alcohols, the monoester are derived from a wide variety of raw materials fatty alcohols, fatty acid alkanolamides, ethoxylated fatty alcohols, fatty acid alkanolamides, their etho-xylates, and others. All these raw materials—with the exception of the branched chains—may be obtained from natural renewable resources. 

Clear, surface-active phosphate ester compositions were prepared by heating 1 mol P4O,0 with 2-4.5 mol of a linear or branched chain C6, 8 saturated alcohol, a C4 20 mono- or dialkylphenol, or a 2- to 14-mol ethylene oxide adduct of one of these alcohols or alkylphenols at 25-110°C, and hydrolyzing the reaction product at 60-110°C with 0.5-3.0% H20. The hydrolyzed mixture had a lower Klett color value than the phosphorylation reaction mixture [21]. 

The Fischer-Tropsch synthesis, which may be broadly defined as the reductive polymerization of carbon monoxide, can be schematically represented as shown in Eq. (1). The CHO products in Eq. (1) are any organic molecules containing carbon, hydrogen, and oxygen which are stable under the reaction conditions employed in the synthesis. With most heterogeneous catalysts the primary products of the reaction are straight-chain alkanes, while the secondary products include branched-chain hydrocarbons, alkenes, alcohols, aldehydes, and carboxylic acids. The distribution of the various products depends on both the type of catalyst and the reaction conditions employed (4). 

Because the thermal separation of products has been substituted by a liquid-liquid separation, the two phase technology should be best suited for hydroformylation of longer chain olefins. But with rising chain length of the olefins the solubility in the aqueous catalyst phase drops dramatically and as a consequence the reaction rate. Only the hydroformylation of 1-butene proceeds with bearable space-time yield. This is applied on a small scale for production of valeraldehyde starting from raffinate II. Because the sulfonated triphenylphosphane/rhodium catalyst exhibits only slow isomerization and virtually no hydroformylation of internal double bonds, only 1-butene is converted. The remaining raffinate III, with some unconverted 1-butene and the unconverted 2-butene, is used in a subsequent hydroformy-lation/hydrogenation for production of technical amylalcohol, a mixture of linear and branched C5-alcohols. 

Ordinarily, DCo(CO)4 would be expected to add to an olefin to an appreciable extent by anti-Markownikoff addition, since with olefins more straight chain than branched chain product results. Such addition would place deuterium on the penultimate carbon atom. It can be argued that allyl alcohol is not an olefin and therefore might be expected to behave differently. As usual more work is necessary. A similar isomerization of allyl alcohol to propanal using FelCO) has been reported by Emerson and Pettit (24). 

The primary application of these alcohols is the manufacture of anionic or nonionic surfactants for personal cleansing products, most of which end up in your wastewater treatment plants and rivers. Microorganisms don t chew up branch-chain surfactants as well as they do the straight ones. It used to be, for example that the surfactant based on the sodium salt of dodecyl benzene sulfonate, a 12-carbon branch chained anionic surfactant, was found to be slowing, down water treatment processes. Dodecyl alcohol as a raw material for these surfactants has been largely replaced by laurel alcohol, a 12-carbon straight-chain, linear alcohol. If you look at the bottle next time you shampoo your hair and rinse, you ll see sulfonates based on laurel alcohol listed, but none based on dodecyl. 

---