Yields of products from

Single-pass conversions of acetone cyanohydrin are 90—95% depending on the residence times and temperatures in the generator and hold tank. Overall yields of product from acetone and hydrogen cyanide can be >97%. There are no significant by-products of the reaction other than the sodium salts produced by neutralization of the catalyst. 

Coal-based pitches are predommantly byproducts of metallurgical coke operations in recovery-type coke ovens. The volatile products from the coke oven are recovered and processed, in simplest terms, into gas, light oils, and tar. The quantity and character of the materials are influenced by the type of coal charge, the design of the cokmg equipment, and the temperature and time profile of carboni2ation. Table 1 shows a typical yield of products from the... 

Likewise, hydrogenation of WVGS 13423 at 350°C mcreased the yield of product from about 34 to 74 wt% Not unexpectedly, hydrogenation at 400°C increased conversion even more to 83 wt%, while hydrogenation at 450°C produced a recoverable product yield of 67 wt% The apparent reduction m yield upon reaction at 450°C is discussed below. 

The total yield of products from alkanecarboxyhc acids increases, in most cases, by addition of anhydrous hydrogen fluoride. The optimum hydrogen fluoride concentration is much higher than catalytic and is related to the basicity of a carbonyl group. A mechanism for the formation of both 1,1,1-trifluoroalkanes and bis(l,l-difluoroalkyl) ethers has been proposed [206] (equation 102)... 

Grant et a/.397 examined the reactions of hydroxy radicals with a range of vinyl and a-methylvinyl monomers in organic media. Hydroxy radicals on reaction with AMS give significant yields of products from head addition, abstraction and aromatic substitution (Table 3.8) even though resonance and steric factors combine to favor "normal tail addition. However, it is notable that the extents of abstraction (with AMS and MMA) arc less than obtained with t-butoxy radicals and the amounts of head addition (with MMA and S) are no greater than those seen with benzoyloxy radicals under similar conditions. It is clear that there is no direct correlation between reaclion rale and low specificity. 

The values of ks/kp for partitioning of carbocations are most conveniently determined as the ratio of the yields of products from the competing nucleophile addition and proton transfer reactions (equation 1 derived for Scheme 2). The determination of these product yields has been simplified in recent years by the application of high-pressure liquid chromatography (HPLC). Typically, the product peaks from an HPLC analysis are detected and quantified by UV-vis spectroscopy. In cases where the absorbance of reactants and products is small, substrates may be prepared with a chromophore placed at a sufficient distance so that its effects on the intrinsic reactivity of the carbocationic center are negligible. For example, the aliphatic substrates [1]-Y have proved to be very useful in studies of the reactions of the model tertiary carbocation [1+].21,23... 

Figure 3. Yields of products from dry and wet processing of field pea and fababean flours and their protein and starch concentrations in percent.

The stractural and elemental analyses (contents of C, H and O) of biomass samples are given in Table 6.2. Table 6.3 shows the yields of products from three biomass samples by pyrolysis at different temperatures. As seen in Table 6.3, the pyrolysis process yields gaseous products, tarty hquid, and tar. In general, the yields of gaseous products from each run increase with increasing pyrolysis temperature. The yields of gaseous products from the pyrolysis increase from 34.4 to 43.9% for hazelnut shell, from 35.1 to 47.4% for tea waste and from 32.1 to 40.7% for spruce wood with increasing of temperature from 700 to 950 K. 

Table 6.3 Yields of products from biomass sampl es by pyrolysis at different temperatures ...

Maintenance within stated limits of the yield of product from the culture. 

Onium salts have been widely used as an acid generator for photo-, EB, and x-ray resist. In addition, aromatic polymers such as novolak and polyhydroxystyrene have been often used as a base polymer for EB and x-ray resist. The reaction mechanisms in a typical resist system have been investigated by pulse radiolysis [43,52,77-88], SR exposure [79,80,83-85], and product analysis [88]. Figure 6 shows the acid-generation mechanisms induced by ionizing radiation in triphenylsulfonium triflate solution in acetonitrile. The yields of products from electron beam and KrF excimer laser irradiation of 10 mM triphenylsulfonium triflate solution in acetonitrile are shown in Fig. 7 to clarify the... 

Figure 7 Yields of products from electron beam and KrF excimer laser irradiation of 10 mM triphenylsulfonium triflate solution in acetonitrile.

In the presence of approximately 1% cobalt naphthenate in benzene, only 4 hours at 100°C. were required to decompose the hydroperoxide almost completely. The yields of products from decompositions catalyzed by some commonly used cobalt and vanadium (1) compounds are given in Table I. Polymerization appears to be the major reaction. 

Determine the selectivity and reactivity of. CH, from the yields of products from methylene insertion in pentane ... 

The reactivity of alkanecarboxylic acids towards sulfur tetrafluoride decreases as their acidity increases (decreasing pAia values) and as steric hindrance increases. 107 108 Thus, trifluoroacetic acid does not give hexafluoroethane, even at 250 C, and trimethylacetic acid (pivalie acid) at 140 C gives 2-methyl-2-(trifluoromethyl)propane in only 10% yield (Table 3). The total yield of products from alkanecarboxylic acids, in most cases, increases by addition of 0.2-2 moles of anhydrous hydrogen fluoride.35... 

Table I (104) shows the yields of products from maltose to malto-pentaose recovered from digests of 0.2 M crystalline a-D-glucosyl fluoride with crystalline a-amylase preparations from six different biological sources. The digests were incubated at 30 °C for 10 minutes, heat inactivated, and chromatographed for product isolation and analysis.

Figure 11.18 Yields of products from the thermal neutron-induced fission of 235U. (From A. C. Wahl. Nuclear Charge Distribution in Fission, in New Directions in Physics, N. Metropolis, D. M. Kerr, and G. C. Rota, Eds. Copyright 1987 by Academic Press, Inc. Reprinted by permission of Elsevier.)...

Concerns about nonproductive reactions of radicals apply not only to carbon-carbon bond forming steps, such as additions and cyclizations, but to every step in a sequence of radical reactions. For example, to obtain a good yield of product from the reaction in equation (2), not only must the addition of R to A=B occur but the conversion of R—A—B- to a nonradical product must also be efficient. In a chain reaction, the slowest propagation step must still be rapid relative to loss of the radicals by radical-radical or radical-solvent reactions. In practice, reactions with rates of product formation of 102—103 s 1 are experimentally difficult to conduct. Reactions with rates of 104—10s s 1 are manageable and those with rates >106 s l are usually conducted with ease. 

Table IV. Yields of Products from Distillation and Coking...

Yields of Products from Vinyl Phosphonium Salts... 

Doyle et al.344 and Wee and Liu345 have reported the ring-closing transformation of a-diazoacetamides 108 and 109 to yield 2(3//)-indolinones over Nafion-H [Eq. (5.136)]. In the transformation of compounds 109 the electrophilic intramolecular substitution is followed by decarboxylation.345 Small amounts of 2-azetidinone derivatives (4—10%) formed through a carbene intermediate were also detected. The yield of products from compounds 108 are even higher than observed in the presence of Rh(OAc)2 often applied in the decomposition of diazo compounds.344... 

We suggest that the cyclodextrin cavity provides an environment wherein recombination of the geminate radical pair (from Type I) is favored and this results in lower yield of products from Type I process relative to Type II. Experiments are underway to test this cage effect with other examples. 

TABLE III. - Yields of products from distillation and blending... 

The yield of products from 1,8-naphthalic anhydride was low, partly because of the thermal stability of the anhydride (Fields and Meyerson, 1967e). At 690° with 20 sec contact time, 50% was recovered unchanged. 

Figure L Yields of products from Tet-ralin and the ratio of trans/cis Decalin as a function of added Western Kentucky, Homestead mine coal...

Just occasionally it is possible to carry out cross-condensations between two different enolizable molecules under equilibrating conditions, A notable example is the base-catalysed reaction between methyl ketones and lactones. With sodium hydride—a strong base that can convert either starting material entirely into its enolate anion—good yields of products from the attack of the enolate of the ketone on the electrophilic lactone can be obtained. 

TABLE 28.9 Yield of Products from Destructive Distillation of One Ton of Dry Hardwood... 

Reactions of organomagnesium compounds with sulfoxides often result in ligand exchange [31], and may be complicated by a- or ortho metallation. However, in some cases, notably with 2-pyridyl aryl sulfoxides, reactions with arylmagnesium halides give useful yields of products from displacement of the aryl sulfoxido group [32, 33], e.g. [32]... 

A more complexing solvent such as A, A-dimethylacetamide (DMAC) gave higher yields of products from the exchange reaction of a penta-fluorophenylcopper reagent with various organic halides, compared to reactions in THF and BU2O (97). 

The importance of the a-fluorine atoms is clearly demonstrated by the low yield of product from the coupling of 1,1,1-trifluoroiodoethane with iodobenzene and the failure of w-butyl iodide to couple under similar conditions 200). -Butyl iodide gave 1-butene only, and no evidence was reported to suggest the formation of a thermally unstable butyl-copper compound. A previous attempt to react methyl iodide with copper also failed 119). 

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