Cyclo-octanone

In yet another version of adopting a biphase system, oxidation of alkanes with rert-butyl hydroperoxide has been conducted with an aqueous phase. Launay et al. (1998) have developed an efficient and highly selective conversion of cyclo-octane to cyclo-octanone using Ru colloidial particles formed in situ from RuCli. 5H2O. The aqueous phase can be recycled. 

A 8-endo-trig cyclization leading to a cyclo-octanone, foreseeable in the case of a o-homoallylic benzoyl tellnride, did not occnr. Snch a resnlt was achieved, however, with a more conformationally nnstrained snbstrate A. Treatment of the product with H2O2 furnishes a 3.7 1 mixture of the desired dibenzocyclooctanone B and the methylene cyclo-heptanone C. 

The kinetics of the potassium hexacyanoferrate(III)-catalysed oxidation of glucose with ammonium peroxodisulfate have been studied.82 The kinetics and mechanism of oxidation of some cycloalkanols by alkaline Fe(CN) have been reported.83 The same group has also studied the oxidation of cycloalkanones under comparable conditions and determined the order of reactivity as cyclohexanone > cyclopentanone > cyclo-octanone > cycloheptanone.84 Palladium(II) has been found to catalyse the oxidation of formaldehyde, thiourea, and thioacetamide by alkaline Fe(CN)g, whereas no effect is observed in the oxidation of acetaldehyde.85 The orders of reaction have been determined and a mechanism was proposed. 

Ring expansion of cyclohexanone to cycloeheptanone may be effected by reaction with diazomethane (Expt 7.17). The ring-expanded ketone is obtained in about 60 per cent yield and is accompanied by some epoxide and some cyclo-octanone which results from further ring expansion of the cycloheptanone. Mechanistically the reaction may be represented in the following manner. 

Table 4. Relative strain energies in cyclo-octanone Conformations...

General Preparations.—Alkenes. Dehalogenation of vicinal dihalides is easily carried out using sodium in liquid ammonia, e.g. 1,2-dichlorocyclo-octane gave ds-cyclo-octene in 95% yield.The scope of the synthesis of ap-unsaturated carbonyl compounds by syn-elimination from 2-phenylselenoxides has been studied only low yields of the desired ketone were obtained from 2-phenylseleno-cycloheptanone and cyclo-octanone because of the competing Pummerer rearrangements, but improved yields could be obtained by prior conversion of the ketones into ketals. The reaction worked well for 2-methoxycarbonyl cyclic ketones, e.g. 2-methoxycarbonylcyclo-oct-2-en-l-one was prepared in 93% yield. ... 

On irradiation, 2-(cycloheptylidene)cycloheptanone isomerizes to 2-(cyclohept-l-enyl)cycloheptanone, which on further irradiation cyclizes to a mixture of all four possible isomers of the oxetan (204). An analogous mixture of oxetans was obtained by irradiation of 2-(cyclo-oct-l-enyl)cyclo-octanone. ... 

Enamines, Enol Acetates, Enol Ethers, and Vinyl Halides.—Diphenylcyclopropene-thione reacts with the morpholine enamines of cyclo-octanone and cyclododecanone to give adducts (337), which gave the strained cyclopropenes (338) when treated with dimethyl acetylenedicarboxylate. Other reactions of (337) have been reported." Whereas reactions of enamines with imidodialkylsulphonium chlorides usually give... 

A detailed study of the solvolysis of vinyl triflates has been carried out using data obtained previously for solvolysis of the vinyl triflate derivatives of cycloheptanone and cyclo-octanone. ... 

Treatment of hepta-1,6-diene with monochloroborane gives a mixture, which was thermally depolymerized and treated with methanol and dichloromethyl methyl ether to give a mixture of cyclo-octanone (major component), 2-methylcycloheptan-one, and 2-ethylcyclohexanone (total yield was 70 %). ... 

Trimethylsilyl acetate-tetra-n-butylammonium fluoride has been recommended as a mild silylating agent, e.g. cycloheptanone, cyclo-octanone, and cyclododecanone were converted into their trimethylsilyl enol ethers (85—95 % yi elds). °... 

A useful conformational probe is the effect of a carbonyl group on the geminal coupling constant of the vicinal protons. This effect was used in an analysis of the H n.m.r. spectrum at — 160°C of [2,2,7,7- H J cyclo-octanone which adopts a boat-chair conformation. The Barfield-Grant relationship was shown to be wrong in the region of 0 = 120°. ... 

Cyclo-octanone was obtained from cyclo-octanol using 2,2,6,6-tetramethylpiperi-dine and two equivalents of per-acid," and has been converted into diperoxide (332 20% isolated) using H2O2 in the presence of anhydrous methanesulphonic acid. Amine-free monolithium acetylide adds to cyclo-octanone to give a good yield of alkynol. Cyclo-octanone reacts with the lithium salt of the 2-(methylthio) oxazole (333) to give thio-epoxide (334) which was desulphurized to methylenecyclo-octane using triphenylphosphine. ... 

Cyclo-octanone tosylhydrazone reacts with sodium methoxide in diglyme to give a... 

At this point the synthesis intersects with an earlier racemic synthesis of Ziegler. Thus the diester is hydrolysed and decarboxylated, and the monoacid re-esterified with diazomethane, giving a 1 1 mixture of conformational isomers (64) and (65), which can be separated easily and re-equilibrated thermally. There is a rather subtle stereochemical point to be noticed here despite the fact that rotation about the aryl-aryl bond occurs, there is no racemisation. The thermal interconversion does not occur through a planar transition state, due to the extreme conformational restraints on the cyclo-octanone bridge. 

General Systems.—Allinger et al. have applied the force-field method to calculations of the energy and conformation of cyclic non-conjugated olefins, including cycloheptene, isomeric cyclo-octeries, cyclo-octadienes, and cyclo-decenes, and cis,cis-cyclodeca-l,6-diene the latter is predicted to exist as a 65 35 chair-boat mixture. Similar calculations have been carried out for various cyclic ketones. Cycloheptanone is expected to exist as a mixture of conformers, whereas cyclo-octanone and cyclononanone should exist as (1) and (2), respectively. The conformation (3 X = Hj) predicted for cyclo-... 

Reaction of benzyne with cycloheptanone enolate gives the ene product 2-phenylcycloheptanone and the adduct (177) in ratios depending on the reaction conditions.Methoxybenzyne gives largely the ene product with both cycloheptanone and cyclo-octanone enolates. Compound (177) has been converted into benzo[3,4]cyclobuta[l,2-h]cycloheptatriene. Cycloheptanone enolates react with 1-chlorocyclohexene and sodium amide to give the related products (178), (179), and (180). ... 

Cycloaddition of dichloroketen to cyclic ketones, including cycloheptanone and cyclo-octanone, gives 3,3-dichloro-oxetan-2-ones (324), which readily thermally decarboxylate to dichloromethylenecycloalkanes. ... 

Cycloheptanone and cyclo-octanone react with n-butyl-lithium and o-... 

Various condensations of cyclo-octanone to give 2,2 -dialkylcyclo-octa-nones, and with ethyl cyanoacetate, have been reported. The u.v. spectra of boron trifluoride complexes of cycloalkanones and the i.r. spectra of titanium tetrachloride complexes have been studied. Reactions of benzo-cycloheptanone are discussed. ... 

Dehydrogenation of cycloheptanone and cyclo-octanone with Pd compounds to give the 2-enones is reported. ... 

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