Saturated ketone olefinations

The major difference in reactivity between CF3OF and FCIO3 lies in the capacity of the former to react with olefins without the benefit of an electron releasing group and even with electron deficient olefins such as a,y5-un-saturated ketones. Reactions with nonactivated double bonds indicate the presence of an oc-fluoro cationic intermediate [e.g., (64)] as exemplified by the reaction with the -3-ketone (63), which yields the fluorophenol (65). 

Olefin formation by reduction of a,/3-un-saturated ketones with diborane, 347 Olefin formation by reductive eliminations, 343... 

Reduction of carbon-carbon double bond Microalgae easily reduce carbon-carbon double bonds in enone. Usually, the reduction of carbonyl group and carbon-carbon double bond proceeds concomitantly to afford the mixture of corresponding saturated ketone, saturated alcohol, and unsaturated alcohol because a whole cell of microalgae has two types of reductases to reduce carbonyl and olefinic groups. The use of isolated reductase, which reduces carbon-carbon double bond chemoselectively, can produce saturated ketones selectively. 

One or both carbonyls in /3-diketones can be reduced, as well as the carbonyl function in acyl cyanides (210). Similar treatment of a,/3-unsat-urated ketones and aldehydes can lead to the saturated carbonyl products via selective reduction of the olefinic bond (207, 208, 210) see Eq. (51) in Section III,A,4. Some terpenes (a- and /3-ionone, pulegone) were reduced in this way (208). Platinum(II) phosphine complexes have been used for the hydrosilylation of saturated ketones and could be used for the reduction (211). 

Several aspects are particularly noteworthy. Good chemoselectivity is noted in the compatibility with epoxides, esters, olefins, and alcohols. Entries 44 and 45 demonstrate the chemoselectivity between an unsaturated and saturated ketone. 

With the intent of exploiting the intramolecular 1,3-diyl trapping reaction, Little and Muller prepared azo compound 663 and decomposed the substance in refluxing acetonitrile (Scheme LXVI) Triquinane 664, isolated in 85% yield, was then degraded to a saturated ketone which was methylated in the angular position prior to olefination. 

Saturated hydrocarbons Olefinic hydrocarbons Aromatic hydrocarbons Halocarbons Mercaptans Sulfides CS2 Ethers Ketones Aldehydes Esters Tertiary amines Nitro compounds (without a-H atoms) Nitriles (without a-atoms)... 

Unsaturated A5-3p-hydroxy steroidic molecules undergo a facile isomerization in toluene solution at 60°C in the presence of Cu on alumina under inert atmosphere. The saturated ketones derived through a formal hydrogen transfer from the alcoholic to the olefinic moiety are formed, besides small amounts of A4-3-ketone. 

Dihydrogeranylacetone, though not a completely simple olefin, is chemoselectively hydrogenated at the C=C bond in the presence of a Ru complex with MeO-BIPHEP analogue containing four P-2-fury 1 groups to afford the saturated ketone with 91 % ee (Scheme 1.31) [86]. Examples of hydrogenation of a trisubstituted olefin with an oxo or oxy substituent in the p-position are unknown. 

Saturated hydrocarbons < olefins < aromatic hydrocarbons = organic halides < sulfides < ethers < nitro compounds < esters = aldehydes = ketones < alcohols = amines < sulfones < amides < carboxylic acids... 

Selective hydrogenation of a,/3-olefinic ketones to saturated ketones can be accomplished through careful control of the temperature, duration of reaction, and use of a catalyst active enough to permit low-temperature hydrogenation. Thus, mesityl oxide, benzalacetone, and benzalaceto-phenone have been reduced in S>0-100% yields to the corresponding saturated ketones. Preparations of nickel catalysts used in these reductions are described. ... 

Acylation of olefins with acid chlorides or anhydrides catalyzed by Lewis acids. When performed in the presence of a saturated hydrocarbon, the product is the saturated ketone. 

During our studies on the use of supported copper catalysts in selective hydrogenation reactions, we found that these systems can be effectively applied to the chemoselective hydrogenation of a,P-unsaturated ketones giving quantitative yields in the corresponding saturated ketone also when another olefinic bond is present in the molecule [3]. 

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