Ketones, cyclopropyl phenyl

MoC15 promotes the ring-opening transformations of cyclopropyl ketones. Cyclopropyl phenyl ketone 251 is converted to 1-phenyl-1,2,4-trichloro-1-butene 252. Desilylative lactonization of propyl 2-(trimethylsilylmethyl)cyclo-propanecarboxylate 253 yields ds-2-chloro-4-pentanolide 254 stereoselectively [144]. (Scheme 100)... 

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

Benzyl-cyclopropane aus Cyclopropyl-phenyl-ketonen allgemeine HerstellungsvorschrifC 25 mMol Keton werden unter Stickstoff in 10 ml abs. THF gelost und bei 0° mit 12,5 m/ m Diboran-Losung in THF versetzt. Man riihrt 1 Stde. bei 20°, gibt 0,31 ml (2,5 mMol) Bortrifluorid-Atherat zu, riihrt einige Stdn. weiter und arbeitet wie iiblich auf. 

The ambivalent aptitude of sulfur [19] to stabilize adjacent anionic as well as cationic centers is a remarkable fact that has shown to be a reliable feature for the assembly of four-membered ring scaffolds utilizing cyclopropyl phenyl sulfides [20]. Witulski and coworkers treated the sulfide 1-69 with TsOH in wet benzene (Scheme 1.19) [21]. However, in addition to the expected cyclobutanone derivative 1-70, the bicyclo[3.2.0]heptane 1-70 was also obtained as a single diastereoisomer, but in moderate yield. Much better yields of 1-71 were obtained using ketone 1-72... 

Alkylation of nonenoRzable ketones. Potassium hydride in THF reduces cyclopropyl phenyl ketone however, in the presence of cryptate [2.2.21 (1 equivalent) the ketone can be alkylated in high yield (equation I). 

The palladium-catalysed intramolecular 3 + 2-cycloaddition of alk-5-enylidene-cyclopropanes produced a variety of bicyclo[3.3.0]octane systems with up to three stereocentres.62 The oxidative addition of cyclopropyl phenyl ketone to Ni(Pcy3) gave nickeladihydropyran, which is a key intermediate in the Ni(0)-catalysed homo-... 

Treatment of cyclopropyl phenyl sulfide60 with w-butyllithium in tetrahydrofuran at 0 °C for 2 hr led to 1-phenylthiocyclopropyllithium 116 61 >, which added to ketones... 

In the case of cyclopropyl derivatives, although cyclopropyl methyl ketone gave a mixture of pentan-2-one and pentan-2-ol, cyclopropyl phenyl ketone afforded cyclopropylphenylmethane or cycloprop-ylphenylmethanol depending on the method of quenching (Scheme 2)P... 

Cyclopropyl phenyl ketone afforded quantitatively n-butylbenzene, instead of cyclopropylphenylme-thane, because of the reactivity of the cyclopropyl group. In the case of 6-methoxytetralone, a dehydrogenation product (50) was obtained in 20% yield together with the desired methylene compound (51) in 33% yield (equation 26). Because the tetraline structure of (51) can be a hydrogen donor, the newly formed product (51) may be consumed during the reaction hence the formation of the naphthalene (50). ... 

C10H10O cyclopropyl phenyl ketone 3481-02-5 501.43 44.022 2 19188 Cl OH1003 m-methoxycinnamic acid, predominantly trans 6099-04-3 498.78 43.766 2... 

Certain tetralones which result from aryl aroylcyclopropanes by tin tetrachloride actionwere utilized in a synthesis of picropodophyllone Similarly, indanones are available from cyclopropyl phenyl ketone whereas reaction of ethyl cyclopropanecar-boxylate in benzene or toluene under Friedel-Crafts conditions gives the same class of compounds in an intermolecular fashion ... 

Another successful alkylation of a cyclopropyl ketone was reported by Handel and CO workers when they reacted cyclopropyl phenyl ketone (211) with excess potassium hydride (5 M equivalents) in the presence of [2.2.2]cryptand methylation with methyl iodide gave 212 in 90% yield. The conditions are crucial without the cryptand, 211 is reduced to the corresponding secondary alcohol in 82 % yield. 

In agreement with Walborsky s results and a recent X-ray structure determination of a-cyano-benzyllithium the calculations nicely show that H2C-CN (0.5 kcal mol and Me2CCN (0 kcal mol have almost no inversion barrier while the a-cyano cyclopropyl anion has a sizeable one (9.3 kcal mol ). Whether in the case of the CHO and COOH substituted cyclopropyl anions a pyramidal configuration with a very small barrier (0.7 and 1.9 kcal mol respectively) exists, is not clear. The barrier may be an artifact of the small basis set, and the enolates may well be planar. In any case, the calculations are again in agreement with the experimental result according to which kgx/ rac case of the optically active cyclopropyl phenyl ketone ( —)-(/ )-252 is unity (see Section IV.B.l.a). 

If the electron-withdrawing group is such that self-condensation does not occur then the anion can be generated in the normal manner. Thus, the anion 349 of cyclopropyl phenyl sulfone (348) can be readily prepared by treatment of the parent compound with n-butyllithium at 0°C in THF. The anion has been shown to condense in excellent yield with aldehydes, ketones, methyl iodide and allyl and benzyl bromides to yield 350. The... 

Cyclopropyl aldehydes, 120-121 Cyclopropyl ketones, 218 Cyclopropyl phenyl ketone, 112 Cyclopropyl phenyl sulfides, 231 Cyclosativene, 24... 

The cyclopropyl anion probably used the most, 1-lithio-l-phenylsulfanylcyclopropane, is obtained when cyclopropyl phenyl sulfide undergoes hydrogen abstraction when treated with butyllithium or another strong base. This anion has been treated with a very large number of aldehydes and ketones and afforded, often in very good yield, a large variety of 1-phenylsul-fanylcyclopropylmethanols (see Table number of cases the cyclopropyl-... 

When a mixture of a cyclopropyl phenyl selenone and a ketone or an aldehyde is treated with potassium tert-butoxide in tetrahydrofuran, metalation of the selenone takes place preferentially and the metalloselenone formed immediately reacts with the carbonyl compound. Oxaspiropentanes are produced almost quantitatively when ketones are used whereas a mixture of oxaspiropentanes and cyclopropyl ketones are obtained when the reaction is carried out with aldehydes, for example, formation of 5 and... 

The same general methodology applied to the preparation of alkenyl(silyl)cyclopropanes (vide supra) was previously developed for preparing alkenyl(sulfanyl)cyclopropanes. In this method, the lithium derivative of cyclopropyl phenyl sulfide (1) was used to alkylate a ketone and the resulting tertiary alcohol 2 was then dehydrated to give the product... 

Benzoylation of cyclopropylidenetriphenylphosphorane (1) with benzoyl chloride results in adduct 10 which is hydrolyzed in alkaline medium to cyclopropyl phenyl ketone (11) and triphenylphosphane oxide. ... 

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