Ketones ratios

KetaZine Processes. The oxidation of ammonia by chlorine or chloramine in the presence of ahphatic ketones yields hydrazones (36), ketazines (37), or diaziddines (38), depending on the pH, ketone ratios, and reaction conditions (101). 

The question about the competition between the homolytic and heterolytic catalytic decompositions of ROOH is strongly associated with the products of this decomposition. This can be exemplified by cyclohexyl hydroperoxide, whose decomposition affords cyclo-hexanol and cyclohexanone [5,6]. When decomposition is catalyzed by cobalt salts, cyclohex-anol prevails among the products ([alcohol] [ketone] > 1) because only homolysis of ROOH occurs under the action of the cobalt ions to form RO and R02 the first of them are mainly transformed into alcohol (in the reactions with RH and Co2+), and the second radicals are transformed into alcohol and ketone (ratio 1 1) due to the disproportionation (see Chapter 2). Heterolytic decomposition predominates in catalysis by chromium stearate (see above), and ketone prevails among the decomposition products (ratio [ketone] [alcohol] = 6 in the catalytic oxidation of cyclohexane at 393 K [81]). These ions, which can exist in more than two different oxidation states (chromium, vanadium, molybdenum), are prone to the heterolytic decomposition of ROOH, and this seems to be mutually related. 

Heinsohn and Ashby (147) have suggested that a variation in the stereoselectivity of reduction with the TIBA ketone ratio may be due in part to the... 

The increase of the alcohol/ketone ratio from the left to the right of the series therefore derives from the fact that the RNu -t- RX electron transfer... 

Certain manganese porphyrins adsorbed on silica or alumina, or intercalated in different mineral matrices such as montmorillonite, are also very efficient in alkane hydroxylation.150 151 Alcohol yields and alcohol ketone ratios are remarkably higher than those obtained with the corresponding soluble manganese porphyrins. Manganese tetra(4-Al-methylpyridiniumyl)porphyrin supported on montmorillonite, for instance, is efficient in the hydroxylation of compounds of low reactivity such as n-pentane and n-heptane.151... 

Asinger s studies demonstrated that product formation is sensitive to the ratio of sulfur to ketone (1), the structure of the ketone, the replacement of ammonia by amines, the temperature and the medium. Room temperature (20-25 °C) reactions in which the ratio of sulfur to ketones is 0.5 favors the formation of 3-thiazoline, 2, as shown in Figure 1. The formation of 5-alkylidene-3-thiazolines, 3, sometimes competes with the formation of 3-thiazolines such is the case when aryl ketones such as l-phenylpropan-2-one and l-phenylbutan-2-one are employed (4). Also the additional presence of hydrogen sulfide promotes the generation of 1,2,4-trithiolanes and 1,2,4,5-tetrathiolanes from ketones ana aldehydes at the expense of 3-thiazoline formation (11-12). Increasing the S/ketone ratio to 8 favors the formation of the 3-imidazoline-5-thione (5), a product which has a greater tendency to result from aryl methyl ketones (3). 

SBs containing two nitrogen atoms as donors may be derived either from condensation of dialdehydes or diketones with an amine in the ratio 1 2 or from reaction of diamines with aldehydes or ketones (ratio 1 2). Alternatively, they can be prepared by condensation of either... 

Comments First pilot-plant batch. Extractive work up with NH3 and methyl isobutyl ketone Extractive work up with NH3 and methyl isobutyl ketone Equilibration implemented. Extractive work up with NH3 and methyl isobutyl ketone Ratio (relative amounts) between H20/DET/Ti = approx. 0.5 2 1 measured by assay/volume of the solution that goes into the salt forming step... 

Cashmeran (DPMI) Celestolide (ADBI) Phantolide (AHMI) Galaxolide (HHCB) Traseolide (ATTI) Tonalide (AHTN) Musk Xylene Musk Ketone Ratio HHCB/AHTN References... 

The ratio of rate coefficients, k/k, may be determined indirectly by comparing ROH/ketone ratios on reaction with each substrate separately or by determining the relative yields of R,C1 and R2C1 or the consumption of reactants in competitive experiments. 

Additional polymer blends comprising PAEK s offering property combinations of potential utility include PSF [Robeson and Harris, 1986 Harris and Robeson, 1989] structurally different poly(aryl ketones) [Harris and Robeson, 1986], PAr [Robeson and Harris, 1992], poly(amide-imide) PAI [Harris and Gavula, 1992], PPS [Robeson, 1987], and other PI [Harris et al., 1992]. Mixtures of structurally different PAEK s were noted to be isomorphic within specific limits of ether/ketone ratios [Harris and Robeson, 1987]. Blends of polybenzimidazole, PBI and several commercial PI (Ultem 1000 and Matrimid 5218) have been studied in depth at the University of Massachusetts and found to be miscible. FTIR studies [Guerra et al., 1988 Kim et al., 1993], NMR studies [Grobelny et al., 1990], thermal, dielectric, and mechanical... 

The reactions were performed in a typical flow reactor with a fixed catalyst bed. Reactant solution (isopropyl alcohol ketone, ratio 3) were dosed using a microdosing pump with HLSV 2 cm of solution per 1g of catalyst-hour. 

The dye sensitized photo-oxygenation of cholest-4-en-3 -ol yields only two products (37, 38), an enone (III) and an epoxy ketone (II) as illustrated. The anomalous aspect of these results is that the enone/epoxy ketone ratio varies by a factor of 150 depending upon the choice of sensitizer. In light of our prediction regarding the variation in the Xg / Ag ratio with Et, we were interested in whether there was a... 

Fe(opba)]20 catalyzes the oxidation of cyclohexane and adamantane with total yields up to 5 % based on the oxidant after 24 h with a ratio A/K of 0.9 and a ratio 3°/2° of 3 (84). These results are in line with a mechanism involving hydroxyl radicals as transient intermediates. In the oxidation of cyclohexane catalyzed by [Fe(tpca)(H20]20 (C104)2, the average alcohol-to-ketone ratio is equal to 7, which is much higher than the value characteristic of radical chain oxidation (54). Also, the stereospecificity observed in the oxidation of cis- and trans-l,2-dimethylcyclohexane (up to 97% retention of configuration) points toward the involvement of a metal-based oxidant (83). A few other complexes showing low to moderate catalytic activity in the oxidation of cyclohexane and/or adamantane are listed in Table IV. 

The cage efficiency predominantly depends on the stability of the R radical that determines the barrier of the cage reaction. Comparing the cage efficiency observed for various substrates such as cyclohexane [17], toluene [19], and ethylbenzene [16] confirms a systematic trend and readily explains the difference in alcohol-to-ketone ratio for those substrates (see Figure 1.4). 

Figure 1.4 Effect of the substrate on the solvent-cage efficiency and alcohol-to-ketone ratio.

Base Combined yield (%) Pyrrole ketone ratio... 

Approaches for the synthesis of adipic acid are shown in Figure 2.12. The basic raw materials are benzene, cyclohexane, phenol, acrylates, and butadiene. The principal commercial processes are based on the oxidation of cyclohexane, which usually proceeds in two stages. The first step entails oxidation with air, yielding either a mixture of cyclohexanone and cyclohex-anol (process 1, Figure 2.12) or predominantly cyclohexanol (process 2, Figure 2.12). These reaction products are oxidized in the second stage with nitric acid to adipic acid. Process 1 employs a soluble cobalt oxidation catalyst [133], reaction temperatures in the range of 150 160°C, pressures between 800 and 1000 kPa, and catalyst concentrations of 0.3-3 ppm. At conversions of 5-10%, the selectivity with respect to the cyclohexanone yclohexanol mixture is about 70 80 mol %, with an alcohol/ketone ratio of about 2 1. In process 2 the oxidation is carried out in the presence of boric acid or its anhydride. This results in mixtures particularly... 

When the molar ratio MejAl ketone was approximately unity, ketones (134)— (137) gave 96% axial alcohols 2,2,6-trimethylcyclohexanone, with an axial methyl, gave 88% axial alcohol. Axial attack decreased in the substituent sequence 4-t-butyl-, 2-methyl-, ds-2,6-dimethyl. The decrease with successive introduction of 2-and 6-equatorial methyl groups was paralleled by a decrease in axial attack with decreased flexibility of the ring system in the sequence 2-methyl-, ds-2-methyl-4-t-butyl-cyclohexanones, and rrans-decalone. With cis-2,6-dimethyl- and 2,2,6-tri-methyl-cyclohexanones, at a MejAl ketone ratio of 2 1, the percentage of axial alcohol... 

The compression effect previously advanced to account for varying stereoselectivity at different MejAl ketone ratios is considered inadequate to account for results obtained with 2-equatorially substituted cyclohexanones. Under these conditions the carbonyl plane of the complex is distorted from chair to half-chair and the 2,6-equatorial substituents are moved upwards (138), with attcndent hindrance to... 

The product ratio from 4-t-butylcyclohexanone is insensitive to temperature. However, for e.g. 2,2,6-trimethylcyclohexanone a large variation of the axial-equatorial alcohol product ratio has been noted. A plot of the logarithm of this quotient vs. l/T at a Me,Al ketone ratio of 2 led to a value E, — E = 4.06 kcal moP, a figure taken as indicative of a difference in mechanism between axial and equatorial attacks. 

Entry Ru catalyst R/R Time (h) Conversion (%) (alcohol ketone ratio)... 

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