Ketones acetophenone

Ketones. Acetone, ethyl methyl ketone, diethyl ketone, acetophenone,... 

Acetone ethyl methyl ketone diethyl ketone acetophenone, ben-zophenone (and their nuclear-substituted derivatives). Cyclohexanone. 

The preparation of benzoylacctone Is another example of the acylation of a ketone (acetophenone) by ethyl acetate to a p diketone (Claisen condensation compare preceding Section) ... 

Just as an aromatic ring is alkylated by reaction with an alkyl chloride, it is acylated by reaction with a carboxylic acid chloride, RCOC1, in the presence of AICI3. That is, an acyl group (-COR pronounced a-sil) is substituted onto the aromatic ring. For example, reaction of benzene with acetyl chloride yields the ketone, acetophenone. 

Histories . The Na salt was first isolated by the reaction of nitric oxide on acet (Ref 2) later the same worker found that the action of nitric oxide and Na hydroxide on any compd contg the acetyl group would give Na MEDNA [compds treated were mesityl oxide, methylisopropyl ketone, acetophenone, and ethyl dimethyl-... 

If, on the other hand, unsymmetrically substituted carbonyl compounds such as monosubstituted benzophenones (X = OCH3, CH3, Cl), tert-butyl methyl ketone, acetophenone, acetaldehyde, or benzaldehyde are used for trapping 39a, diastere-omeric mixtures are formed in each case they could all be resolved except for the products obtained with p-methoxybenzophenone and acetophenone 33>. An X-ray structure analysis has been performed for the E-isomer 57g 36) which, in conjunction with H-NMR studies, permitted structural assignment in cases 56 and 57e, g and h35>. Additional chemical evidence for the structure of the six-membered heterocycles is provided by the thermolysis of 56 a considered in another context (see Sect. 3.1). In general the reaction 39a- 56 or 57 is accompanied by formation of phosphene dimers, presumably via [4 + 4]- and via [4 + 2]-cycloaddition 35). 

Reduction of Other Aldehydes. We examined the reduction of anisaldehyde, p-CH30C6H4CH0 and tolualdehyde, p-CH3(C6H<,)CH0 to examine the effect of electron density on aldehyde reduction. In addition, we also investigated one ketone, acetophenone, C6H5C0CH3. The results of these experiments are given in Table 2. 

Compound (B), being an oxidation product of a ketone should be a carboxylic acid. The molecular formula of (B) Indicates that it should be benzoic acid and compound (A) should, therefore, be a monosubstituted aromatic methyl ketone. The molecular formula of (A) indicates that it should be phenyl methyl ketone (acetophenone). Reactions are as follows ... 

The involvement of trialkylboranes in these reactions was probed by use of the optically active trialkylborohydride 52, shown in Eq. (16) (59). In previous work, 52 had been demonstrated to reduce the prochiral ketone acetophenone to 1-phenylethanol of 17% optical purity (80). Compound 52 was then used to generate the unstable anionic formyls 6, 12, and 26 (Table I) subsequently, acetophenone was added to these reaction mixtures. If Eq. (16) were reversible and 52 were the active hydride transfer agent, 1-phenylethanol of 17% optical purity would be expected. In practice, optical purities of 3.1-11.7% were obtained (39). This indicates some type of trialkylborane involvement in the hydride transfer (the exact role cannot be readily determined by experiment). Therefore, it became important to attempt similar reactions with isolable, purified formyl complexes. 

Acetamido ketones have been prepared in a multicomponent reaction from aromatic aldehydes, enolizable ketones (acetophenone and propiophenone), and acetyl chloride in acetonitrile over Nafion-H1002 [Eq. (5.363)]. High yields are achieved under mild conditions and the catalyst proved to be recyclable. 

Ketones react with a-aminoacids in the same way [68], although reactions are reported to be slower there is only one example with an unsymmetrical ketone (acetophenone) and the diastereomeric excess is not reported. 

Methyl phenyl ketone (acetophenone) 3,5,5-Trimethyl)-2-cyclohexen-l-one (isophorone) O S-CH3... 

Similarly, urea TV, 0-acetal 64 undergoes condensation reaction with weak carbon acids to afford acyclic 1,1-enediamines with the elimination of alcohol and amine42,95. A number of active methyl compounds such as an aliphatic ketone, acetophenone, imino ester and thioacetoamide has been successfully converted to 1,1-enediamines. Lactones, lactams and thiolactams condense with 64 to give enediamines 65 in moderate yields (equation 24). Very weakly activated methyl groups are also reactive towards urea A, 0-acetal 64, and 1,1-enediamines 66-71 are prepared from the corresponding reactants42,95. 

On the other hand, Gavrilova and Gonikberg opened the furan ring with hydrogen, without the use of catalysts.213 The reaction is carried out at high temperature (350-375°) and at a pressure between 240 and 750 atmospheres, in the absence of a solvent. The following products are obtained from 2-methylfuran acetone, methyl ethyl ketone, methyl butyl ketone, methyl amyl ketone, acetophenone, methylpropylcarbinol, w-pentane, and water. The authors suggest that these products are formed by a free radical mechanism. 

The mono-pincer ruthenium(ll) complex was successfully employed in the transfer hydrogenation of ketones (acetophenone, benzophenone, cyclohexanone) with isopropyl alcohol as the hydrogen source. 

Two different cases may occur. If this radical is formed in a succession of styrene units (1), it reacts in the same way as in PS. If it is formed on a styrene unit linked to an acrylonitrile unit (2), three reaction pathways may be envisaged. The alkoxy radical resulting from the decomposition of the hydroperoxide formed on this polystyryl radical may react by 3-scission. Scissions (a) and (b) yield chain ketones, acetophenone end-groups and phenyl and alkyl radicals as previously observed in the case of PS photooxidation mechanism. Scission (c) leads to the formation of an aromatic ketone and an alkyl radical. This alkyl radical may be the precursor of acrylonitrile units (identified by IR spectroscopy at 2220 cm-1), or may react directly with oxygen and after several reactions generates acid groups, or finally this radical may isomerize to a more... 

Many modifications of the original procedure have been developed, furnishing the aminonitriles over a wide range of yields. A convenient procedure consists in adding an alcoholic solution of the carbonyl compound to an aqueous solution of sodium cyanide and ammonium chloride. Both aliphatic and aromatic carbonyl compounds react, e.g., diethyl ketone, acetophenone, and benzaldehyde. Similar treatment of formal-... 

The LAH complex of the chiral spirodiol (5) has recently been prepared. This complex exhibits excellent enantioselectivity in the reduction of some aromatic ketones. Acetophenone is reduced at —80 °C in 98% ee and 80% yield. Reduction of other aryl alkyl ketones also gives excellent stereoselectivity, but the use of this reagent with a variety of ketones has not been studied. The chiral auxiliary can be recovered and reused. 

Recently, the preparation of the chiral biphenyl (6) and its use as a modifying agent with LAH has been reported." A complex of LAH-(6)-EtOH (1 1 1) at —78°C gives the best enantiose-lectivities in the reduction of prochiral ketones. Similar to Noyori s reagent, use of the LAH complex with (S)-(6) leads to the (S)-alcohol. Enantioselectivity is usually high for aromatic ketones (acetophenone 97% ee, 93% yield). This reagent reduces 2-octanone in higher enantioselectivity (76% ee) than 3-heptanone (36% ee). 

---