Reduction of furfural

Furylcarbinol has been prepared by the reduction of furfural with sodium amalgam but the Cannizzaro reaction is the better practical method of preparation. 

Furfural. Furfural is readily obtainable from dehydration of pentoses. Reduction of furfural can lead to a variety of products that are more volatile, more stable and possibly also more useful than furfural itself. Selective reduction of the aldehyde moiety leads to furfuryl alcohol (Scheme 15), whereas further reduction of the furan core will lead to tetrahydrofurfuryl alcohol. Reductive deoxygenation can result in the formation of either 2-methylfuran or 2-methyltetrahydrofuran, which can be used as liquid fuels or solvents. 

Reduction of furfural leads to furfuryl alcohol 63 which can be easily transformed into resins, thus replacing phenol formaldehyde resins (Scheme 21) [115]. A recent apphcation concerns impregnation of wood (furfurylated wood). For instance, high retention of grafted or polymerized furfuryl alcohol improves a variety of properties such as an increased hardness, resistance to microbial decay and insect attack, as well as resistance to chemical degradaticai. Modulus of rupture (MOR), elasticity (MOE), and the dimensional stabihty are also significantly increased. 

O 32.62%. Usually prepd from furfural which is obrained by the processing of corncobs, The oil obtained by steam distillation of roasted coffee bean meal consists of 50% furfuryl alcohol after all organic acids have been removed. Laboratory prepn from furfural by the Cannizzaro reaction Wilson, Org. Syn. coll, vol, 1 (2nd ed.P 1941) p 276 cf U.S, par 2t04Ij94 (to Quaker Oats), C.A. 30. 4515 (1936). Has been obtained by yeast reduction of furfural, Prepd industrially hy the catalytic reduction of furfural using nickel and Cu-CrO catalysis Peters, U.S. pat, 1,906 873 (1933 to... 

An old paper by Lintner and von Liebig in 1911 on the reduction of furfural to furfurol by yeast attracted the interest in 1937 of Mamoh and Vercellone, former students of C. Neuberg. It inspired them to use yeast to reduce 4-androstenedione to testosterone. This was the first example of a successful microbial steroid transformation, to be followed by many more in the early 1950s. 

Parpot P, Bettencourt AP, Chamoulaud G, Kokoh KB, Beigsir EM (2004) Electrochemical investigations of the oxidation-reduction of furfural in aqueous medium application to electrosynthesis. Electrochim Acta 49 397-403... 

Chu, D. B., L. Y. Zhang, J. H. Zhang, and X. J. Yin, 2006. Heterogeneous electro-catalytic reduction of furfural on nanocrystalline Ti02-CNT complex fihn electrode in DMF solution. Acta Phys-Chim A Sinica 22 373-77. 

Lintner, C.J. and von Liebig, H.J. (1911) The reduction of furfural through yeast in alcoholic fermentation. Hoppe Seylers Z. Physiol. Chem., 71,449-454. 

Reduction of furfural by baker s yeast—performed by W. Windisch as early as 1898. 

Microbial transformations, and yeast-mediated conversions in particular, have been widely used since the early days of mankind for the production of dairy products, bread, and alcoholic beverages. Whereas all of these early applications used mixed cultures of microorganisms it was the merit of Pasteur in 1862 [1] to lay a scientific foundation of one of these early applications, namely, the oxidation of alcohol to acetic acid by using a pure culture of Bacterium xylinium. All of these early biotechnological operations have been more or less directed in the areas of agricultural and humane nutrition the reduction of furfural to furfuryl alcohol under anaerobic conditions of fermentation, however, by means of living yeast [2,3] was the first phytochemical reduction of an organic molecule described in the literature. 

Manufacturing. Almost all the THE in the United States is currendy produced by the acid-catalyzed dehydration of 1,4-butanediol [10-63-4]. Only one plant in the United States still makes THE by the hydrogenation of furfural (29). Du Pont recendy claimed a new low cost process for producing THE from / -butane that they plan to commercialize in 1995 (30—32). The new process transport-bed oxidizes / -butane to cmde maleic anhydride, then follows with a hydrogen reduction of aqueous maleic acid to THE (30). 

Esters of diphenylacetic acids with derivatives of ethanol-amine show mainly the antispasmodic component of the atropine complex of biologic activities. As such they find use in treatment of the resolution of various spastic conditions such as, for example, gastrointestinal spasms. The prototype in this series, adiphenine (47), is obtained by treatment of diphenyl acetyl chloride with diethylaminoethanol. A somewhat more complex basic side chain is accessible by an interesting rearrangement. Reductive amination of furfural (42) results in reduction of the heterocyclic ring as well and formation of the aminomethyltetrahydro-furan (43). Treatment of this ether with hydrogen bromide in acetic acid leads to the hydroxypiperidine (45), possibly by the intermediacy of a carbonium ion such as 44. Acylation of the alcohol with diphenylacetyl chloride gives piperidolate (46). ... 

The finely divided lead produced by reduction of the oxide with furfural vapour at 290°C is pyrophoric and chemically reactive. 

Furfuryl mercaptan cannot be prepared according to the classical method using furfuryl chloride and potassium sulfide.2 It has been prepared by reduction of 2-furfuryl disulfide, obtained from furfural and ammonium hydrosulfide.3 The mercaptan has also been obtained in 33% yield 2 by the reaction of furfuryl chloride with thiourea and subsequent decomposition of the intermediate S-2-furfurylisothiourea according to the general method described in Organic Syntheses.4 In the present method, which has been published previously, the use of the very unstable and difficultly available furfuryl halides is avoided.6... 

A catalytic, enantioselective approach towards the synthesis of polyol chains has recently been reported by Carreira et al. and has been applied in a synthesis of the polyol subunit of amphotericin B (Scheme 5) [13]. Aldol addition of the silyl dienolate 26 to furfural (27) catalyzed by the Tol-BlNAP-CuF -complex (2 mol-%) gives rise to the addition product 28 in 95 % yield and >99 % ee after one recrystallization. Spectroscopic evidence indicates that a copper dienolate is formed in situ from the silyl dienolate 26 and is actually the active nucleophile [14], Standard transformations including a j-yw-selective reduction of the ft-hydroxy ketone by the method of Prasad and the oxidative conversion of the furan ring to the car-... 

This method is widely used for the preparation of secondary alcohols from ketones. The reduction of aldehydes is important only when these substances are readily available, e.g., heptanal and furfural. 

Methylfuran is best prepared by the vapor-phase hydrogenation of-furfural over a copper chromite catalyst at 1 atm. and 200-300°. Full experimental details have been given. Homologs have been made by reduction of 2-acylfurans by the Wolff-Kishner procedure. ... 

Another method for reductive amination of carbonyl compounds is based on the electroreduction of oximes in aqueous media. Thus, sugar oximes were reduced to their corresponding glycamines in good yields (Hg, KCl, acetate buffer). Similar reductions of oximes derived from furfural, salicylaldehyde, benzophenone and cyclohexanone have also been described, " but reports of preparative electrolyses in strictly aprotic media seem to be absent in the literature. 

Furfuryl Alcohol.—An alcohol, fnrfuryl alcohol, is also known obtained from the aldehyde by reduction. This reduction is brought about by treatment with alcoholic potassium hydroxide, one molecule of the aldehyde being reduced at the expense of a second molecule which is thereby oxidized to the acid. Thus one molecule of pyromucic acid and one of furfuryl alcohol are obtained from two molecules of furfural. 

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