Ketone organometallic reagents

Ketones can be prepared by trapping (transmetallation) the acyl palladium intermediate 402 with organometallic reagents. The allylic chloride 400 is car-bonylated to give the mixed diallylic ketone 403 in the presence of allyltri-butylstannane (401) in moderate yields[256]. Alkenyl- and arylstannanes are also used for ketone synthesis from allylic chlorides[257,258]. Total syntheses of dendrolasin (404)f258] and manoalide[259] have been carried out employing this reaction. Similarly, formation of the ketone 406 takes place with the alkylzinc reagent 405[260],... 

Organometallic reagents react with cyanothiazoles to give thiazolyl ketones (87). 

The ketones can be obtained by addition of organometallic reagents to acids and their derivatives. 

In most cases, the product ratio can be controlled by choice of reaction conditions. Ketones are isolated under conditions where the tetrahedral intermediate is stable until hydrolyzed, whereas tertiary alcohols are formed when the/Tetrahedral intermediate decomposes while unreacted organometallic reagent remains. Bxamples of synthetic application of these reactions will be discussed in Chapter 7 of Bart B. 

Table 8.2. Stereoselectivity in Addition of Organometallic Reagents to Some Chiral Aldelqrdes and Ketones"...

The perfluoroarylcopper reagents react with perfluoroalkylated acid fluorides to give ketones in excellent yields. Solvent, type of organometallic reagent,... 

The presence of unsaturation in the side chain is also compatible with antihistaminic activity. Mannich condensation of p-chloroacetophenone with formaldehyde and pyrollidine affords the amino ketone, 109. Reaction with an organometallic reagent from 2-bromopyridine gives 110. Dehydration leads to triproli-dine (111). ... 

Reaction of Nitriles with Organometallic Reagents Grignard reagents add to a nitrile to give an intermediate imine anion that is hydrolyzed by addition of water to yield a ketone. 

Nitriles are similar in some respects to carboxylic acids and are prepared either by SN2 reaction of an alkyl halide with cyanide ion or by dehydration of an amide. Nitriles undergo nucleophilic addition to the polar C=N bond in the same way that carbonyl compounds do. The most important reactions of nitriles are their hydrolysis to carboxylic acids, reduction to primary amines, and reaction with organometallic reagents to yield ketones. 

Reaction with an organometallic reagent to yield a ketone or an alcohol... 

The initial formation of an ate complex by attack of the nucleophile on the aluminum reagent, followed by reaction with the ketone, is unlikely since treatment of the ketone with a mixture of MAD and the organometallic reagent gave results comparable to those obtained with the organometallic reagent in the absence of MAD. 

The addition of organometallic reagents to a-amino ketones e.g., 1 normally obeys Cram s rule the dominant diastereomer is the. syrc-compound81. 

I.5.3.5.2. Addition to a-SuIfiny l-a,/MJnsaturated Ketones Achiral Organometallic Reagents... 

Bicyclic ketones react with organometallic reagents to give the products of addition from the less hindered face of the carbonyl group. 

Organopalladium intermediates are also involved in the synthesis of ketones and other carbonyl compounds. These reactions involve acylpalladium intermediates, which can be made from acyl halides or by reaction of an organopalladium species with carbon monoxide. A second organic group, usually arising from any organometallic reagent, can then form a ketone. Alternatively, the acylpalladium intermediate may react with nucleophilic solvents such as alcohols to form esters. 

The reactants can be prepared by chelation-controlled addition of organometallic reagents to a-(l-ethoxyethoxy)methyl ketones. Selective sulfonylation occurs at the... 

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