Ketone definition

Synonyms PEEK Polyarylene ether ether ketone Definition Partially cryst. thermoplastic with exc. chem./heat/flame/tear resist. compds. feature exc. flex, and tens. str. and elec, props, at high temps., toughness and abrasion resist. 

Classification Aromatic ketone Definition Obtained by condensation of acetyl chloride and m-xylene in presence of aluminum or ferric chloride Empirical C10H12O Formula CH3COC6H3(CH3)2 Properties Colorless to yish. oil liq., floral sweet odor m.w. 148.21 dens. 0.998 (20/4 C) b.p. 120 C (10 mm) flash pt. > 100 C ref. index 1.543 (20 C)... 

Classification Nonaromatic ketone Definition Most frequently occurring in nature of four optically active isomers of menthone found in oils such as pennyroyal, peppermint, geranium Empirical CioHiaO... 

Synonyms PEK Polyarylene ether ketone Definition Thermoplastic with exc. flame and chem. resist., toughness, abrasion resist. 

CAS 89-82-7 EINECS/ELINCS 201-943-2 Synonyms Cyclohexanone, 5-methyl-2-(1-methylethylidene)-, (R)- (R)-2-lsopropylidene-5-methylcyclohexanone (R)-(+)-p-Menth-4(8)-en-3-one (R)-p-Menth-4(8)-en-3-one (R)-5-Methyl-2-(1-methylethylidene) cyclohexanone Pulegon Pulegone (+)-Pulegone (+)-(R)-Pulegone (R)-(+)-Pulegone Classification Nonaromatic ketone Definition Ketone found in pennyroyal and dedeoma oil Empirical CioHieO Properties Oily liq. pleasant odor of peppermint/camphor misc. with alcohol, ether, chloroform pract. insol. in water m.w. 152.26 dens. 0.936 b.p. 224 C flash pt. 185 F ref. index 1.4870... 

Ciassification Aromatic ketone Definition Commercial prod, is a mixt. of cis- and trans-isomers with trans-isomer predominating Empiricai C31H46O2 Formuia CH3C10H4O2C20H39 Properties Yel. vise, oil or cryst. odorless insol. in water sparingly sol. in methanol sol. in ethanol, acetone, benzene, petrol, ether, hexane, dioxane, chloroform, ether, other fat soivs., veg. oils m.w. 450.68 dens. 0.984 m.p. -20 C ref. index 1.525 Toxicoiogy LD50 (oral, mouse) 25 g/kg LDLo... 

Methyl parasept Classification Aliphatic ketone Definition Ester of methyl alcohol and p-hydroxybenzolc acid... 

More definitive evidence for the formation of an oxirene intermediate or transition state was presented recently by Cormier 80TL2021), in an extension of his earlier work on diazo ketones 77TL2231). This approach was based on the realization that, in principle, the oxirene (87) could be generated from the diazo ketones (88) or (89) via the oxocarbenes 90 or 91) or from the alkyne (92 Scheme 91). If the carbenes (90) (from 88) and (91) (from 89) equilibrate through the oxirene (87), and if (87) is also the initial product of epoxidation of (92), then essentially the same mixture of products (hexenones and ketene-derived products) should be formed on decomposition of the diazo ketones and on oxidation of the alkyne this was the case. 

Protonation of the a-carbanion (50), which is formed both in the reduction of enones and ketol acetates, probably first affords the neutral enol and is followed by its ketonization. Zimmerman has discussed the stereochemistry of the ketonization of enols and has shown that in eertain cases steric factors may lead to kinetically controlled formation of the thermodynamically less stable ketone isomer. Steroidal unsaturated ketones and ketol acetates that could form epimeric products at the a-carbon atom appear to yield the thermodynamically stable isomers. In most of the cases reported, however, equilibration might have occurred during isolation of the products so that definitive conclusions are not possible. 

The study of optical isomers has shown a similar development. First it was shown that the reduction potentials of several meso and racemic isomers were different (Elving et al., 1965 Feokstistov, 1968 Zavada et al., 1963) and later, studies have been made of the ratio of dljmeso compound isolated from electrolyses which form products capable of showing optical activity. Thus the conformation of the products from the pinacolization of ketones, the reduction of double bonds, the reduction of onium ions and the oxidation of carboxylic acids have been reported by several workers (reviewed by Feokstistov, 1968). Unfortunately, in many of these studies the electrolysis conditions were not controlled and it is therefore too early to draw definite conclusions about the stereochemistry of electrode processes and the possibilities for asymmetric syntheses. 

Earlier in this chapter, we learned definitions for the terms oxidation and reduction. We saw that oxidation involves an increase in oxidation state. For example, oxidation of a secondary alcohol will produce a ketone ... 

Products detected or isolated from these oxidations include the corresponding a-hydroxy ketone and a-diketone and also adipic acid (from cyclohexanone) in up to 95 % yield. However, IrCI gives a-chloroketone in quantitative yield . Evidently when the rate of oxidation exceeds enolisation attack is on the keto form, probably via a complex, although this is definite only for Ce(IV) perchlorate, to give a radical, e.g. 

TS-1 is a material that perfectly fits the definition of single-site catalyst discussed in the previous Section. It is an active and selective catalyst in a number of low-temperature oxidation reactions with aqueous H2O2 as the oxidant. Such reactions include phenol hydroxylation [9,17], olefin epoxida-tion [9,10,14,17,40], alkane oxidation [11,17,20], oxidation of ammonia to hydroxylamine [14,17,18], cyclohexanone ammoximation [8,17,18,41], conversion of secondary amines to dialkylhydroxylamines [8,17], and conversion of secondary alcohols to ketones [9,17], (see Fig. 1). Few oxidation reactions with ozone and oxygen as oxidants have been investigated. 

In this chapter, the definitions used by Perrin in his book on pA a prediction (which also includes a very convenient compilation of o values) will be used. One must be alert to the importance of the number of hydrogens directly attached to the carbonyl carbon several groups have pointed out that aldehydes and ketones give separate but parallel lines, with formaldehyde displaced by the same amount again. What this means is that given one equilibrium constant for an aldehyde (or ketone) one may estimate the equilibrium constant for other aldehydes (or ketones) from this value and p for the addition using a value from experiment, if available, or estimated if necessary. This assumes that there is no large difference in steric effects between the reference compound and the unknown of interest. 

The alkyl ketone candidates With definition of the finasteride manufacturing process came a new challenge. The most efficient synthesis of the second generation candidate would make use of the penultimate in the finasteride process 33 as starting material (Scheme 3.25). With a pilot plant campaign to make 3 scheduled, realizing this objective became a priority. None of the methods reported in the literature for ester to ketone conversion had been applied to a hindered steroidal C17 ester. 

Carbohydrates are characterized by the presence of polyhydroxylic aldehyde or polyhydroxy-lic ketone structures or polymers made of such units. Sugars and polysaccharides have definite... 

Based on the above information, the CAMD problem definition is revised as follows - The solvent can be acyclic hydrocarbons and ketones (aromatic compounds, chlorides, dioxanes are not considered for EH S concerns). The normal boiling point should be higher than that of chloroform (334 K), the molecular weight could be between 70-120, the solvent must not form azeotrope with either acetone or chloroform, and, must be totally miscible with the binary mixture of acetone and chloroform. 

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