Ketones non-enolizable

Acid derivatives that can be converted to amides include thiol acids (RCOSH), thiol esters (RCOSR), ° acyloxyboranes [RCOB(OR )2]. silicic esters [(RCOO)4Si], 1,1,1-trihalo ketones (RCOCXa), a-keto nitriles, acyl azides, and non-enolizable ketones (see the Haller-Bauer reaction 12-31). A polymer-bound acyl derivative was converted to an amide using tributylvinyl tin, trifluoroacetic acid, AsPh3, and a palladium catalyst. The source of amine in this reaction was the polymer itself, which was an amide resin. 

N,N-Bis(trimethylsilyl)carbodiimide 328, which is readily accessible in 81% yield on silylation of cyanamide with TCS 14/triethylamine [124] and which is apparently in equilibrium with N,N-bis(trimefhylsilyl)cyanamide 553, reacts readily with non-enolizable ketones such as 554 or 2,5-dimethyl-p-quinone in the presence of CsF or TiCL., probably via 553, to N-cyanoimines such as 555 or 556, in 47 and 89% yield, respectively, and HMDSO 7 [125, 126] whereas the enohzable ketone... 

Base-induced cleavage of non-enolizable ketones leading to carboxylic amide derivative and a neutral fragment in which the carbonyl group is replaced by a hydrogen. 

The good results obtained with aldehydes prompted us to extend this process to ketones. The yields into trifluoromethyl alcohols are lower into this case. As a matter of fact, the reaction works well (30 to 57% in yield) only with non-enolizable ketones such as benzophenone or fluorenone. Moreover, the yields into alcohols are around 5% from cyclohexanone or acetophenone and CF3H is mainly produced. Scheme 9 may be depicted with PhCOCH3. 

Photochemical pinacolization reactions of non-enolizable ketones have been the subject of many investigators.248 Photolysis of benzophenone in... 

This is a reaction of non-enolizable ketones. Optical activity in the R- group is maintained. 

Apart from the Takai method and titanium reagents such as 15, silyl reagents 16 and 17 frequently find application in the synthesis of vinylic silanes from carbonyl compounds. Reagent 16 can be utilized with aldehydes and non-enolizable ketones in a reaction analogous to the Peterson olefination Reagent 17 also reacts successfully with enolizable ketones.6... 

Non-enolizable ketones with a relatively low reduction potential, such as benzophenone, can serve as the carbonyl component used as the hydride acceptor in this oxidation. 

Recently new methods have been introduced using mercury(II) nitrate trihydrate, Mn02, KMn04 and BaMn04 catalyzed with AICI3 in CH3CN at room temperature for the deprotection of benzylic dithioacetals of aldehydes and non-enolizable ketones. ... 

Studies of simple furan-3-ol derivatives are still sparse. The ketonic tautomers are better known in the sense that 2,2-disubstitution stabilizes them not only against isomerization but also against oxidation. These non-enolizable ketones are considered very briefly. 

The base converts enolizable ketones almost quantitatively into the corresponding enolates. Non-enolizable ketones react in the manner formulated for benzophenone ... 

Similar findings have been reported by Ishikawa and coworkers. Using the disilacyclobutene (100) as the key reactant, they have found that disilacyclopentane and -ene products, e.g., (102)-(107), can be obtained using non-enolizable ketones <930M87>, alkenes, dienes <930M4987, 950mii4>, or alkynes <95JOM(499)35> with nickel or platinum catalysis—presumably via metal insertion intermediates such as (101) ( heme 12). 

When non-enolizable ketones are treated with NaNH2 in aromatic solvents (generally benzene or toluene) at reflux, the cleavage of a carbon-carbon bond is obtained leading to the formation of an amide and a hydrocarbon (ref. 108), this... 

The Cleavage of Non-enolizable Ketones with Sodium Amide K. E. Hamlin and Arthur W. Weston... 

The Haller-Bauer reaction is mechanistically related to alkoxide fissions. In this reaction a non-enolizable ketone is cleaved by sodamide into an amide and a hydrocarbon 93... 

All ketones, aldehydes, and esters mentioned so far have had an a-carbon that can lead to an enol, which means that there was a hydrogen on that carbon that could be removed by base. When a ketone does not have such a proton (it is a non-enolizable ketone), treatment with strong base can lead to a C—C bond cleavage reaction. Discovered by Semmeler,52 Haller and Bauer developed the reaction illustrated by reaction of 63 with NaNH2 to give amide 65. Acyl addition of the amide anion to the carbonyl of the ketone led to 64, and loss of the anion Ph" gave the amide product. Workup protonates the anion to give, in this case, benzene. This... 

B.V. The Stobbe Condensation. When succinic ester derivatives (such as diethyl succinate, 215) are condensed with non-enolizable ketones or aldehydes in the presence of base, the initial condensation product is 216. The alkoxide reacts with the distal ester via acyl substitution to give a lactone intermediate (217). In the original version of this reaction, saponification of 217 gave the a-alkylidene monoester, 218. The reaction is not completely general and is limited to those a, co-diesters for which the Dieckmann condensation is not a... 

Carboxylic acids from non-enolizable ketones COOH... 

Cleavage of non-enolizable ketones with sodium amide frequently applied to formation of trisubstituted acetic acid ... 

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