Ketones, cyclobutyl phenyl

Methyl-l -phenylpropan-1 -one Cyclopentyl phenyl ketone Cyclobutyl phenyl ketone Cyclopropyl phenyl ketone 4-Benzhydrylbenzophenone 9-Acetylfluorene... 

Utilizing selenoxide syn elimination as the key step, a two-step procedure has been developed for the conversion of ketones to enones.22 Cyclobutyl phenyl ketone (52) and 3-phenylcyclobu-tanone (55) were both transformed via the phenyl selenides to the corresponding 1-cyclobutenyl phenyl ketone and 3-phenyIcyclobut-2-en-l-one in 74 and 26% overall yield, respectively.22... 

Triethylsilane in trifluoroacetic acid has proved to be a mild and selective reducing agent for the conversion of aryl and diaryl ketones into the corresponding arenes however, with activated benzaldehydes, e.g, 4-MeCeH4-CHO, Friedel-Crafts alkylation competes with reduction. Reduction of phenyl cyclobutyl ketone and phenyl cyclopropyl ketone gives low yields (36 and ca. 25%, respectively) of the corresponding benzylcycloalkanes [the former reaction also affords phenylcydo-pentane (ca. 42%) via ring-expansion] and with ortAo-benzoylbenzoic acid and 3-benzoyIpropanoic acid the lactones (11) (100%) and (12) (86%), respectively, are formed. ... 

Irradiation of cyclobutyl phenyl ketone (179) in isopropyl alcohol leads to 180, while irradiation in benzene leads to 181 and 182. Propose mechanisms for formation of the products, and explain why different products are formed in the two solvents. 

The importance of the stereoelectronic conformation in determining the path of reaction may be seen in the example of phenyl cyclobutyl ketone. Photolysis of this compound yields 60% of the highly strained bicyclopentane shown below and only 40% of open-chain olefin(84) ... 

It is interesting to note that the latter result is exceptional since l,l-bis(phenyl-seleno)cyclopropane is the only selenoacetal derived from ketones to be at least partially cleaved under these conditions and even the homologous cyclobutyl derivative is inert under these conditions. This may be due to the extra stabilization introduced by the cyclopropyl ring. The case of 2-decy 1-1,1-bis(methylseleno)cyclo-propane merits further comment. It is difficult to assess whether the cleavage of the carbon-selenium bond occurs on the methylseleno moiety cis or tram to the alkyl group, since this organometallic leads to a mixture of the two possible stereoisomers on further reaction with electrophiles (Scheme 16). 

The general method of converting ketones into the corresponding a -unsaturated ketones by conversion of the ketones into the phenylselenoketones, followed by oxidation and elimination of benzeneselenic acid, has been applied to phenyl cyclobutyl ketone and 3-phenylcyclobutanone. ... 

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