Acetyl acetonate precursors

Nickel nanorods (diameter 12 to 15 nm length, 50 to 100 nm) have been synthesized by a solvothermal decomposition of nickel acetate in the presence of n-octylamine (nickel acetate to w-octylamine molar ratio is 1 300) at 250°C (104). The formation of Ni nanorods is favored by the presence of n-octyl amine it reduces, under solvothermal conditions, the Ni ions to Ni° and also acts as a shape-controlling agent to produce metallic nickel nanorods. In the absence of linear alkyl amines, only NiO nanoparticles are produced. Using a similar approach, in the presence of w-octylamine, nanorods of ruthenium and rhodium metals have been produced starting from corresponding acetyl acetonate precursors, Ru(acac)3 and Rh(acac)3. The metallic nanorods are stable in air because of the amine coating and can be redispersed in hydrocarbon solvents. 

LDHs synthesized by sol-gel synthesis methods have smaller crystallites and high BET surface area in comparison with materials synthesized by the coprecipitation method. It is based on dissolution of the alkoxide precursor of M" cations by acid hydrolysis (HCl or HNO3), and gradual addition of a solution of acetyl-acetonate precursors at a constant pH value controlled by NH OH. After the gel is obtained, it is washed with ethanol and then dried [2, 20]. 

YBa2Cu307 films are also obtained by MOCVD from a mixture of acetyl acetonates (tetramethyl heptadionate) of yttrium, barium, and copper, typically at a pressure of 5 Torr and at a deposition temperature of These precursor materials... 

Effect of Catalyst Composition. Where acetic is the typical acid substrate, effective ruthenium catalyst precursors include ruthenium(IV) oxide, hydrate, ruthenium(III) acetyl-acetonate, triruthenium dodecacarbonyl, as well as ruthenium hydrocarbonyls, in combination with iodide-containing promoters like HI and alkyl iodides. Highest yields of these higher MW acids are achieved with the Ru02-Mel combination,... 

The quantitative assay for PBG and ALA (Bio Rad, Hercules, CA, USA) that is based on the classical method by Mauzerall and Granick may be used for determination of the porphyrin precursors. PBG is absorbed by the anion-exchange column and ALA by the cation-exchange column interferences are washed out. After elution from the column, ALA is derivatized by acetyl acetone to form a pyrrole. Both ALA and PBG are determined colorimetrically with the modified Ehrlichs reagent. Instead of this broadly used standard method ALA, but not PBG may be detected and quantified using amino acid chromatography. However, our experience has shown that this method is only valid for detecting massively increased concentrations of ALA. 

A number of compounds with the protoilludane skeleton have been synthesized (Scheme 40). The two keto-esters (279) and (280) have been converted by standard methods into a variety of tricyclic analogues. In addition, the bicyclic enone (281), obtained from 4,4-dimethylcyclopentene and acetyl-acetone by a similar procedure, has been converted into protoillud-7-ene (282) (Scheme 41). A long and rather low-yield synthesis of (283), a possible precursor of illudinine (284), has been reported. ... 

It seems to be well-established that methane and ketene are formed in the main reaction, while carbon monoxide, ethylene and other products, produced in trace amounts, are probably the result of the ketene decomposition. Ethane and acetonyl acetone are chain termination products (see later), while the precursor of acetyl acetone is probably the radical formed in the reaction of the acetonyl radical and the ketene. 

In the case of other systems prepared by adsorption of gold acetyl acetonate, it seems that only cationic gold complexes could be active in CO oxidation. In the case of Au/NaY zeolite the Au precursor is reduced to Au under reaction conditions at 298 K with no evidence of formation of Au [164]. The catalyst shows activity although the Au complex (initial catalyst) is an order of magnitude more active than Au. The authors, however, report that the catalyst is less active than... 

For V(acac)3 characteristic precursor vibrations which was also obsoved for unsupported solid VO(acac)2 [8]. Furthermore, the spectrum of silica-supported V(acac)3 shows a broad vibration at 1713 cm characteristic for compounds comaining carboityl groups like acetyl acetone, acetone or acetic acid weakly adsorbed on silica [8, 10], The spectrum of adsorb V(acac)3 on alumina corresponds more to the spectrum of acetyl acetone adsorbed as an enolate on alumina (bands at 1605 cm l, 1576 cm i, 1535 cm i, 1400 cm i and 1375 cm [8]) than to the spectrum of the unsupported solid. Also for alumina-supported V(acac)3 a band at 1462 cm i due to surface carbonate was identified. 

Metal carbonyls have been widely used as metal precursors [37-59] because they are easily available and fulfill most of the requirements mentioned above, but particularly because CO ligands are easily removed from the solid after thermal decomposition. Vapor- or liquid-phase impregnation with platinum acetyl-acetonate, Pt(acac)2, which is a comparatively small and easily sublimable complex, has been used by Hong et al. [19] to load platinum in various zeohtes. The... 

Acetyl CoA is the precursor for all three ketone bodies, acetoacetate, 3-hydroxybutyrate, and acetone. 

The three compounds, acetoacetate, acetone, and 3-hydroxybutyrate, are known as ketone bodies.60b The inability of the animal body to form the glucose precursors, pyruvate or oxaloacetate, from acetyl units sometimes causes severe metabolic problems. The condition known as ketosis, in which excessive amounts of ketone bodies are present in the blood, develops when too much acetyl-CoA is produced and its combustion in the critic acid cycle is slow. Ketosis often develops in patients with Type I diabetes mellitus (Box 17-G), in anyone with high fevers, and during starvation. Ketosis is dangerous, if severe, because formation of ketone bodies produces hydrogen ions (Eq. 17-5) and acidifies the blood. Thousands of young persons with insulin-dependent diabetes die annually from ketoacidosis. 

One of the earliest reported preparations of the requisite glycosidation precursor 5-deoxy-l,2,3-tri-0-acetyl-p-D-ribofuranoside (17) was published by Kissman and Baker in 1957.23 D-Ribose was heated at reflux in a methanol/acetone mixture in the presence of concentrated HCI to provide methyl 2,3-O-isopropylidene-D-ribofuranosidc (21), which was in turn converted to the corresponding 5-O-mesyl ribofuranoside 22 with methanesulfonyl chloride in pyridine in 63% yield. The sulfonate moiety of 22 was then displaced with sodium iodide in refluxing DMF to provide 5-deoxy-5-iodo derivative 23 in 76% yield on a multigram scale. Reductive dehalogenation of 23 was accomplished under heterogeneous catalytic hydrogenation conditions to provide the reduced 2,3-0-protected intermediate 24 in 56% yield, which was subjected to hydrolysis conditions in... 

Acetyl-CoA is regenerated in this process. The overall product yields in moles per mole of glucose converted are approximately 0.5 acetate, 0.75 butyrate, 2 CO2, and 2 H2 2.5 mol ATP are formed. The nonacidic compounds, acetone, 1-butanol, and 2-propanol, are formed by transformation of some of the acetoacetyl-CoA into acetoacetic acid, which is the precursor of acetone and 2-propanol. Some of the butyryl-CoA is the precursor of 1-butanol via intermediate butyraldehyde. Ethanol is formed by reduction of small amounts of acetyl-CoA. The end result of the production of the neutral products by these additional pathways is that the yields of the other products are reduced. The neutral products are in a lower oxidation state than the acidic products and require additional reducing power as NADH to be formed. Some of the product Hj serves to sustain and provide NADH because higher partial pressures of H2 during the fermentation promote higher yields of the neutral products, whereas removal of the product H2 as it is formed has the opposite effect. 

The answer is d. (Murray, pp 190-198. Scriver, pp 1521-1552. Sack, pp 121-138. Wilson, pp 287-317.) Ketone bodies include acetoacetic acid and P-hydroxybutyrate, which are formed in the liver, and acetone, which is spontaneously formed from excess acetoacetate in the blood. Starvation results in glycogen depletion and deficiency of carbohydrates, causing increased use of lipids as energy sources. Increased oxidation of fatty acids produces acetyl coenzyme A (CoA) and acetoacetyl CoA, a precursor of ketone bodies. Although the liver synthesizes ketone bodies from excess... 

The model monosaccharides just listed were prepared from common precursor IV.l (Scheme 39), which was readily obtained by azidonitration of 3,4,6-tri-O-acetyl-D-galactal followed by deacetylation with sodium methoxide. Treatment of IV.l with acetone and toluene p-sulfonic acid monohydrate at room temperature led to predominant formation of the thermodynamically favored 3,4-O-isopropylidene (IV.2) in 61% yield while also producing 27% of the 4,6-O-isopropylidene derivative IV.3. The position of the isopropylidene IV.2 was verified by the use of NMR chemical shift analysis to confirm the position of the acetate group in the resultant acetylated adduct IV.4. Synthesis of the 4-O-sulfate derivative (IV.7) from IV.2 utilized a step that differentiated the 3-OH and 4-OH positions after benzylation and de-isopro-pylidination of IV.2, a selective methylation at the 3-OH of diol IV.5 was achieved via a tin procedure [91] to give methyl glycoside IV.6. Conversion of the azide into... 

Although P-l-units feature prominently in products from various acidolytic treatments, they have been extraordinarily difficult to find by NMR of lignins isolated by dioxane water extraction, but have been reported [28,30,34,59,134,275,276]. In part this was because of overlapping signals in ID and 2D experiments. Ede et al. initially estimated that the level was <2% in pine [28]. It was later found that P-l-units were more efficiently extracted into acetone-water fractions, or by direct derivatization and extraction into acetic anhydride [276]. TOCSY spectra clearly authenticated P-l-units for the first time. The structure is rather convincingly revealed in spectra of an acetylated poplar MWL [50,78,134]. It is likely that this acidic extraction converted other P-l-precursors in lignins to the conventionally described P-l-products, as discussed further below. The most extensive model data is from Miyakoshi and Chen [243,244]. Other data derives primarily from reports on the synthesis of such model compounds [250,277,278]. 

The 1 H-doz.[ 13Jannulene (35) has been generated from the bicyclic precursor (36) by irradiation in acetone 31 the product is believed to have the stereochemistry represented in (36). l/f-Aza[13]annulene itself appears from n.m.r. studies to be endowed with significant aromatic character, whereas the A -acetyl and JV-methoxycarbonyl derivatives are not. The first 2J7-quinolizine derivative (37) has been described and is obtained along with other products by irradiation of the benzo[c]quinolizine (38) in benzene.32 The precise mechanism of this reaction... 

Treatment of crude (-)-83 with Me3Si0S02CF3 in CH2CI2 (0 °C), followed by acetylation (Ac20/pyridine, 25 °C) and recrystalHzation from EtOAc furnishes the diastereomerically pure naphthacenyl methyl ketone (-)-85 (55%). Baeyer-Villiger oxidation with Se02 and H2O2 leads to (-)-86 (94%), which upon oxidation (4 N Jones-reagent, acetone, 0-20 °C) and saponification (1 N NaOH/THF, 20 °C) affords (-)-87 in 80% yield, a known precursor of (-)-7-deoxyidarubicinone [240,241]. 

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