Alcohol aerobic

Oxidation of alcohols. Aerobic oxidation of alcohols requires Co(OAc)2 as well as RuCI] and an aldehyde for cooxidation. Yields of acids or ketones are excellent (9 examples, 78-98% yield). 

Cloudiness and off-flavors. Volatile phenols (4-vinylguaiacol), ethyl acetate, amyl acetate (higher alcohols). Aerobic spoilage potential limited to beers stored in the presence of air. However, under suitable conditions, they grow rapidly and often give rise to films on the surface of the beer as well as resulting in the production of hazes and off-flavors. 

Liu J, Wang N, Szostek B et al (2010) 6-2 Fluorotelomer alcohol aerobic biodegradation in soil and mixed bacterial culture. Chemosphere 78 437-444... 

In addition, a number of the developed catalysts are also active, under different experimental conditions, in oxidations of other substrates, in particular some of the copper catalysts for alcohol aerobic (TEMPO-mediated) or peroxidative oxidations [21, 22]. The reactions may be microwave-assisted (details are given in Chapter 18). 

Scheme 5.15 Allyl ic alcohol aerobic kinetic resolution.

Maturation is conducted in closed, full containers to prevent oxidation and aerobic growth of microorganisms. Etee air contact with low alcohol wine soon leads to vinegar. Except for those sherry types already mentioned, wines ate exposed to air minimally and temporarily. During transfers incident to bulk storage and processing, some air exposure is almost inevitable, mote in total the longer the wine is held. In the cases of white and pink table wines, it is ordinarily as neat zero as possible, and stainless steel or other impermeable containers, inert gas headspace, etc ate employed. Red wines withstand and even benefit from small but repeated exposures to air. 

Novel aerobic oxidation method using A-hydroxyphthalimide as a catalyst (transformations of hydrocarbons to alcohols and/or carbonyl compounds) 99YGK24. 

In fermentation for the production of acetic acid, ethyl alcohol is used in an aerobic process. In an ethanol oxidation process, the biocatalyst Acetobacter aceti was used to convert ethanol to acetic acid under aerobic conditions. A continuous fermentation for vinegar production was proposed for utilisation of non-viable A. aceti immobilised on the surface of alginate beads. 

Alcoholic fermentation, ethanol production, has been best known for a few decades by S. cerevisiae. Many obligate aerobic fungi, such as common moulds of the genera Aspergillus, Fusarium and Mucor are also well known for their ability to produce ethanol.2 The benefits are ... 

Resting cell of G. candidum, as well as dried cell, has been shown to be an effective catalyst for the asymmetric reduction. Both enantiomers of secondary alcohols were prepared by reduction of the corresponding ketones with a single microbe [23]. Reduction of aromatic ketones with G. candidum IFO 5 767 afforded the corresponding (S)-alcohols in an excellent enantioselectivity when amberlite XAD-7, a hydro-phobic polymer, was added to the reaction system, and the reduction with the same microbe afforded (R)-alcohols, also in an excellent enantioselectivity, when the reaction was conducted under aerobic conditions (Figure 8.31). 

For the deracemization of phenylethanol derivatives using G. candidum under aerobic conditions (Figure 8.41b), the (S)-specific enzyme was reversible and (R) enzyme was irreversible, so (R)-alcohol accumulated when the cell and racemic alcohols were mixed [31b,c]. Para-substituted phenylethanol derivatives gave better results than meta-substituted derivatives. Sphingomonas was used for... 

Fig. 3. Protein synthesis in a maize primary root during ( ) one hr pulse labelling with [ HJleucine under aerobic conditions (b)-(e) pulse labelling with [ HJIeucine during the specified times under anaerobic conditions. The arrow labelled TPs indicates the position of the transition polypeptides. The unlabelled arrow indicates the position of alcohol dehydrogenase 1 (ADHl). From Sachs et al. (1980).

The complex Pd-(-)-sparteine was also used as catalyst in an important reaction. Two groups have simultaneously and independently reported a closely related aerobic oxidative kinetic resolution of secondary alcohols. The oxidation of secondary alcohols is one of the most common and well-studied reactions in chemistry. Although excellent catalytic enantioselective methods exist for a variety of oxidation processes, such as epoxidation, dihydroxy-lation, and aziridination, there are relatively few catalytic enantioselective examples of alcohol oxidation. The two research teams were interested in the metal-catalyzed aerobic oxidation of alcohols to aldehydes and ketones and became involved in extending the scopes of these oxidations to asymmetric catalysis. 

All the Ru-based racemization catalysts described earUer are air-sensitive and thus difficult to reuse. We found that a modified Ru complex 7 was air-stable and recyclable, in particular, in a polymer-supported form 8. The racemization of secondary alcohols with 7 took place equally well under both oxygen and argon atmospheres. The subsequent DKRs of several alcohols using 7 or 8 under aerobic... 

This pathway is supported by the demonstration of benzyl alcohol dehydrogenase, benzaldehyde dehydrogenase, benzoyl-CoA ligase, and benzoyl-CoA reductase activities in cell extracts (Biegert and Fuchs 1995). The benzyl alcohol dehydrogenase from benzyl alcohol-grown cells was similar in many of its properties to those from the aerobic bacteria Acinetobacter calcoaceticus and Pseudomonas putida (Biegert et al. 1995). 

The oxidation of alcohols to the corresponding carbonyl compounds is one of the key reactions in organic synthesis and nnmerous methods have been developed over the years to accomplish this transformation [16], A general mechanism for Pd-catalysed aerobic oxidation is shown below (Scheme 10.5). 

Scheme 10.6 Mechanism of aerobic oxidation catalysed by complex 13 [23] Table 10.2 Oxidative kinetic resolution of alcohols using (-)-sparteine [25]...

In situ generated Ni-IPr complexes were also active in this oxidation reaction, however higher catalyst loadings (5 mol%) and temperatures (60°C) were required to enable the reaction. A proposed mechanism for the aerobic oxidation of alcohols in presented in Scheme 10.8. 

Kim, S.S. St Rajagopal, G. (2004) Efficient Aerobic Oxidation of Alcohols to Carbonyl Compounds with NHPI/CAN Catalytic System. Synthetic Communications, 33, 2237-2243. 

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