Equation products

The in equation 4.19 relates to the fact that this is not the true standard deviation, but an estimate to measure the process shift (or drift) in the distribution over the expected duration of production. Equation 4.20 is the best estimate for the standard deviation of the distribution as determined by CA with no process shift. 

Electrophilic nitrosation of the carbanion generated from the reaction of an organic base with a strong organic acid, such as a-hydrohexafluoroisobutyronitnle [2], a hydrohexafluoroisobutyric acid or its acid chloride [2], or a hydrotetra fluoroethanesulfonyl fluoride [4], yields the corresponding a-nitroso compound as the major product (equations 2 and 3) The a-hydrohexafluoroisobutyric acid or acid chloride reacts with excess trifluoroacetyl nitrite in dimethylformamide to afford the O substituted oxime [3] (equation 4)... 

Perfluoroalkylation of substituted benzenes and heterocyclic substrates has been accomplished through thermolysis of perfluoroalkyl iodides in the presence of the appropriate aromatic compound Isomeric mixtures are often obtained W-Methylpyrrole [143] and furan [148] yield only the a-substituted products (equation 128) Imidazoles are perfluoroalkylated under LTV irradiation [149] (equation 129). 4-Perfluoroalkylimidazoles are obtained regioselectively by SET reactions of an imidazole anion with fluoroalkyl iodides or bromides under mild conditions [150] (equation 130) (for the SET mechanism, see equation 57)... 

It IS likely that the syn selectivity exhibited in cycloadditions of fluoroallene IS due to electrostatic interactions [23 25] As in the case of difluoroallene the reactions of fluoroallene with diazoalkanes and nitrile oxides are facile, but such reactions, other than that shown in equation 18, are neither regio nor stereospeutic [23, 25] Indeed, the addition of phenylnitrile oxide to fluoroallene occurs with preferential anti addition for both regioisomenc products (equation 20)... 

Reaction of sulphoxides with disulphides 493 in the presence of BuLi or NaH yields mono-, and disulphenylated products (equation 297). The formation of monosulpheny-lated sulphoxide as the main reaction product (55%) takes place only when Et2S2, sulphoxide and BuLi are used in a 1 3 3 ratio556. 

Monoalkylamines give only the cyclic products, i.e. lV-alkyltetrahydro-l,4-thiazin-l-oxides 542 (equation 341), while dialkylamines afford the mono- and diaddition products (equation 342)633. Hydroxylamine undergoes double addition to substituted divinyl sulphoxides 543 to give thiazine 1-oxides 544634 (equation 343). 

A reasonable mechanism is shown in equation 23 methyllithium attacks the sulfur atom, giving the secondary carbanion 36 by cleavage of the four-membered ring. A rapid proton transfer produces the sulfonyl-stabilized carbanion 37 which reacts with the added electrophile to give the product (equation 23)3. 

Meinwald and coworkers71 studied the chemistry of naphtho[l, 8-bc]thiete and its S-oxides. The reaction of the sulphone 2 with LAH (equation 29) is of particular and direct relevance to this section since it is different from the reductions that have been discussed thus far, because the major reaction pathway is now cleavage of an S—C bond, rather than a deoxygenation of the sulphur atom. The major product (equation 29) was isolated in 65% yield two minor products accounted for a further 15% yield. One of the minor products is 1-methylthionaphthalene and this was most probably produced by an initial reduction of the strained 1,8-naphthosulphone, 2, to the thiete, which was then cleaved to the thiol and subsequently methylated. Meinwald also showed71 that the thiete was subject to cleavage by LAH as well as that both molecules were susceptible to attack and cleavage by other nucleophiles, notably methyllithium. These reactions are in fact very useful in attempts to assess a probable mechanism for the reduction of sulphones by LAH and this will be discussed at the end of this section. 

Sulphoximines may also be obtained from sulphoxides by reaction with benzene- and toluenesulphonyl azides179,180. Yields are often nearly quantitative and the reaction is usually carried out in the presence of copper. This reaction shows a high degree of stereospecificity181, for example, if (R)-methyl p-tolyl sulphoxide is the reactant then (S)-methyl-S-p-tolyl-lV-p-toluenesulphonylsulphoximine is the product (equation 66). It has been suggested that this reaction involves the intermediacy of a nitrene species182. 

Our analysis of the reaction of nitrogen dioxide molecules is not unique. The same type of path can be visualized for any chemical reaction, as Figure 6-20 shows. The reaction enthalpy for any chemical reaction can be found from the standard enthalpies of formation for all the reactants and products. Multiply each standard enthalpy of formation by the appropriate stoichiometric coefficient, add the values for the products, add the values for the reactants, and subtract the sum for reactants from the sum for products. Equation summarizes this procedure ... 

Further utility of the Andersen sulphoxides synthesis is demonstrated by the preparation of optically active unsaturated sulphoxides which were first prepared by Stirling and coworkers from sulphinate 276 and the appropriate vinylic Grignard reagents. Later on, Posner and Tang prepared in a similar way a series of ( )-l-alkenyl p-tolyl sulphoxides. Posner s group accomplished also the synthesis of (+)-(S)-2-(p-tolylsulphinyl)-2-cyclopentenone 287, which is a key compound in the chiral synthesis of various natural products (equation 159). 

The carbanions of 1-alkenyl sulphoxides 400 also react with carbonyl compounds to give the corresponding condensation products (equation 237). Solladie and Moine have used this type of reaction in their enantiospecific synthesis of the chroman ring of a-tocopherol 401. Addition of the lithio reagent 402 to the aldehyde 403 affords the allylic alcohol 404 in 75% yield as a sole diastereoisomer (equation 238). 

Se-phenyl areneselenosulfonates (24) undergo facile free-radical addition to alkenes to produce / -phenylseleno sulfones (25) in excellent yield (see Scheme 7). The addition occurs regiospecifically and affords anti-Markovnikov products contrary to the analogous boron trifluoride catalyzed reaction which produces exclusively Markovnikov and highly stereospecific products (equation 37). Reaction 36 has been shown to have the radical... 

The Fenske Equation can be used to estimate the composition of the products. Equation 9.35 can be written in a form ... 

Cyclopentadiene has been reported to undergo photocycloaddition with l,l-dichloroethylene,(27) difluorodichloroethylene,<27> and 1,2-dichloroethy-lene(60) to yield the following products, equations (10.44)-(10.46). 

Cycloreversion of the 277-pyrido[l,2- ][l,3,5]triazine-2,4(3//)-dione derivatives could be achieved by flash vacuum thermolysis (FVT). FVT of 89 at 530 °C gave two isocyanates 90 and 91, which were not isolated but detected by IR spectroscopy <2002ARK438>, whereas FVT of 3-(2-pyridyl) analog of 89 afforded 91 as the only product (Equation 5) <2000J(P2) 1841 >. 

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