Carbonyl series

C=C stretch 80 C-13 chemical shifts 22, 53 C60 31,32 C60O isomers 54 carbon dioxide 120, 182 carbon monoxide 175,191 carbonyl series 84 carbonyl stretch 84, 220 in solution 244 Carmichael 136 Carpenter 152, 196 Cartesian coordinates 52, 286, 287 CASSCF keyword 228 CASSCF method 228,229,230,231, 232,233, 234,235 state-averaged 233... 

Furthermore, solvent, temperature and substituent effects on pXHB are also presented and dual substituent parameters have been introduced into two carbonyl series (CH3)2NC(0)X (X = CF3, CH2C1, H, CH3, NMe2) and CH3C(0)X (X = CH3CO, CF3, H, F, CH3, OCH3, NMe2) and related to the following equation ... 

On the theoretical hand, calculations have been performed as soon as in the 50ies [56,63] since formaldehyde represents the smallest member of the carbonyl series. References to early works are avalaible in the compilation by Davidson and McMurchie [64] and in references [56-58,63]. Of particular interest for a comprehensive assignment of the experimental transitions are the very fine and accurate calculations by Harding and Goddard using their GVB-CI method [60,65]. 

In the case of the octaosmium carbonyl, it is not clear whether the heptaosmium carbonyl anion has 20 or 21 carbonyl groups in the ion. If the latter is the case, then the ion corresponds to the "electron -precise system according to or the Wade theory, and arises from an "electron-deficient neutral carbonyl species. These reactions are of considerable preparative utility for the Os6/Os5 system, and, as has been amplified in the discussion of the pentaosmium carbonyl series, form a natural... 

Fit . 8. NMR diagnosis of M-methylene complexes. The diagram indicates the chemical shift ranges (8CH, above 8CH, below) found for 95% of all metalcarbenes (type A), M-methylene complexes (type C), alkanediyl complexes (type G), and metal alkyls belonging to the metal carbonyl series (see text). 

Ketones have a general formula (C H2n+i)2C=0. Propanal and propanone are the first isomers of the carbonyl series to have the same molecular formula CjHeO. They are functional group isomers. (See Unit 6A.)... 

Formaldehyde, the parent compound of the carbonyl series, is unstable as a monomer. However, the acid-catalyzed depolymerization of paraformaldehyde produces the monomer as vapors that may by absorbed in ethereal solvents or that may be codistilled with tetrahydrofuran. " The resulting solutions can be conserved for days or even weeks at -25 °C in a deep-freezer. Generally, in the 0.5-1.0 M range, the concentration can be readily assessed by iodometric titration. 

Hammen equation A correlation between the structure and reactivity in the side chain derivatives of aromatic compounds. Its derivation follows from many comparisons between rate constants for various reactions and the equilibrium constants for other reactions, or other functions of molecules which can be measured (e g. the i.r. carbonyl group stretching frequency). For example the dissociation constants of a series of para substituted (O2N —, MeO —, Cl —, etc.) benzoic acids correlate with the rate constant k for the alkaline hydrolysis of para substituted benzyl chlorides. If log Kq is plotted against log k, the data fall on a straight line. Similar results are obtained for meta substituted derivatives but not for orthosubstituted derivatives. 

Analysis This is a 1,6-dicarbonyl compound so a recormection is called for. The next obvious series (frames 36-8) of discormections ends up at 382B - not an easy compound to make. Where could we put a carbonyl group in 382A to allow some more helpfiil discormections ... 

Hoffmann (1). a student of Hantzsch, used the condensation of selenobenzamide with a-halogenated carbonyl derivatives to prepare a series of 2-phenylselenazoles according to the Scheme 1,... 

The replacement of selenoamide by selenourea in the Hantzsch s synthesis. (1st method) leads to 2-aminoselenazoles 2, 14. 15). This series of compounds has been well developed, mainlv because selenourea is much more easily accessible than the selenoamides, but also because a wide variety of a-halogenated carbonyl compounds are available for the Hantzsch s evdization reaction (Scheme 5). 2-Aminoselenazole itself was prepared from commercially available chloroacetaldehyde semihydrate... 

It is well known that in nitrogen-containing heterocyclic compounds the reactivity of alkyl groups is enhanced. In the thiazole series, alkyl groups in the 2-position are reactive towards carbonyl compounds and condensations may be realized. 

A major difference between alcohols and thiols concerns their oxidation We have seen earlier m this chapter that oxidation of alcohols gives compounds having carbonyl groups Analogous oxidation of thiols to compounds with C=S functions does not occur Only sulfur is oxidized not carbon and compounds containing sulfur m various oxida tion states are possible These include a series of acids classified as sulfemc sulfimc and sulfonic according to the number of oxygens attached to sulfur... 

Another series of antiinflammatory carboxyhc acids that ate derived from cortienic acid (107), a minor adrenal metabohte, has been described (104,105). Esterification of both the 17a-hydroxyl group and the carboxyhc acid of (107) were requited to develop a compound of high topical potency with low systemic activity. Peak activity was generally associated with a 17a-propionoxy group and a 17P- uoromethoxy carbonyl (eg, (108)), or 17P-methoxycarbonyl residue. 

The reaction is initiated with nickel carbonyl. The feeds are adjusted to give the bulk of the carbonyl from carbon monoxide. The reaction takes place continuously in an agitated reactor with a Hquid recirculation loop. The reaction is mn at about atmospheric pressure and at about 40°C with an acetylene carbon monoxide mole ratio of 1.1 1 in the presence of 20% excess alcohol. The reactor effluent is washed with nickel chloride brine to remove excess alcohol and nickel salts and the brine—alcohol mixture is stripped to recover alcohol for recycle. The stripped brine is again used as extractant, but with a bleed stream returned to the nickel carbonyl conversion unit. The neutralized cmde monomer is purified by a series of continuous, low pressure distillations. 

Carbonyl compounds can be primary (from radicals or hydroperoxides) or secondary (from alcohols). Thus the picture emerges of hydrocarbon oxidations occurring through compHcated series-sequential pathways as in Figure 1, where clearly other reactions could be going on as well. All possible pathways are pursued to some extent traffic along any pathway is a function of energy requirements and relative concentrations. 

Manufacture. Trichloromethanesulfenyl chloride is made commercially by chlorination of carbon disulfide with the careful exclusion of iron or other metals, which cataly2e the chlorinolysis of the C—S bond to produce carbon tetrachloride. Various catalysts, notably iodine and activated carbon, are effective. The product is purified by fractional distillation to a minimum purity of 95%. Continuous processes have been described wherein carbon disulfide chlorination takes place on a granular charcoal column (59,60). A series of patents describes means for yield improvement by chlorination in the presence of dihinctional carbonyl compounds, phosphonates, phosphonites, phosphites, phosphates, or lead acetate (61). 

The main synthetic route to high nuclearity metal carbonyl clusters involves a condensation process (/) a reaction induced by coordinatively unsaturated species or (2) a reaction between coordinatively saturated species in different oxidation states. As an example of (/), Os2(CO)22 can be condensed to form a series of higher coordinated species (89). 

Positionalisomeri tion occurs most often duting partial hydrogenation of unsaturated fatty acids it also occurs ia strongly basic or acidic solution and by catalysis with metal hydrides or organometaUic carbonyl complexes. Concentrated sulfuric or 70% perchloric acid treatment of oleic acid at 85°C produces y-stearolactone from a series of double-bond isomerizations, hydration, and dehydration steps (57). 

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