Cyclooctanone Compound

Pyrroles 36 with n = 4, 8 have been isolated and characterized (Table XIX). These include4,5,6,7,8,9-hexahydro-l//-cycloocta >]pyrrole (yield 60%, optimal synthesis time about 3 hr), which shows a reduced stability as compared with other pyrroles of this series (n = 2,3,8). Nevertheless, the reason for the unsuccessful attempt to synthesize this compound from cyclooctanone oxime and acetylene [87JCS(P 1)2829] is not very clear. 

Claisen condensations always involve esters as the electrophilic partner, but enolates of other carbonyl compounds—ketones, for example—may work equally well as the enol partner. In a reaction with a carbonate, only the ketone can enolize and the reactive carbonate ester is more electrophilic than another molecule of the ketone, A good example is this reaction of cyclooctanone. It does not matter which side of the carbonyl group enolizes—they are both the same, v. 

The methyl ester of 3,7-dimethyl-8-hydroxyoctanoic acid have been prepared in good yields and with ee >98% by deprotonation of the starting trimethyl cyclooctanone 57, R = Me using (R,R) 3 and LiCl at — 78 °C (Scheme 37)77. This reaction is a key step in a versatile synthesis of optically active isoprenoid, which is present as a sub-unit in vitamins, plant metabolites, antibiotics and other naturally occurring compounds. 

Aziridine enamines of cycloheptanone (12, n = 2) and cyclooctanone (12, n = 3) have been prepared70 by the titanium tetrachloride method, but cyclohexanone gave only compounds 13, 14 and 15. 

Dynamics of Eight-Membered Rings in the Cyclooctane Class Table 9. Barriers in cyclooctanone and related compounds... 

A nuclear magnetic resonance study ( H, Te) of these reaction mixtures established that ketonyl tellurium trichlorides and diketonyl tellurium dichlorides are present. The easily crystallized and less soluble compounds were isolated. Contrary to Morgan s claim, ethyl methyl ketone did react to give bis[2-oxo-l-butyl] tellurium dichloride albeit in very low yield. Alkyl ethyl ketones and tellurium tetrachloride produced very low yields of bis[3-oxo-2-alkyl] tellurium dichlorides. Cyclooctanone and tellurium tetrachloride in refluxing carbon tetrachloride gave bis[2-oxocyclooctyl tellurium dichloride (m.p, 174°) in 40% yield . 

As described above, zeolites can also act as solid base catalysts when the Si Al ratio is low and the extra framework cation is a large one such as The most basic common exchanged zeolite is CsX. With this material the aldol condensation of cyclooctanone with benzaldehyde gave only the monobenzylidene compound (Eqn. 10.23) 5 while reactions using piperidine, m nesium oxide or amorphous cesium aluminosilicate gave both the mono- and di-benzylidene products(Eqn. 10.12). The smaller ketones, cyclohexanone and... 

I crmaleic acid can be used in the Baeyer-Villiger reaction, as illustrated for the case of cyclooctanone. It epoxidizes terminal olehns eflSciently at a low temperature l -oclene affords the epoxide in 80% yield at 0° but at 25° the yield is only 40%. In I he case of the more reactive internal olefins the epoxide ring is cleaved even at 0° to give the diol monomaleate. Aromatic amines with electron-withdrawing substituents MIC oxidized to nitro compounds. 

Examples of symmetrical tetroxanes 48 prepared by this method are shown in Table 3. Aldehydes afforded high yields of tetroxanes 48, as did cyclohexanone derivatives, but the relatively strained cyclopentanone and larger ring compounds such as cyclooctanone and cyclodecanone gave only trace amounts of tetroxanes. Di- -alkyl ketones provided generally good yields of tetroxanes whereas ketones with branched alkyl chains gave little or no tetroxane product (Table 3). 

Bergman and Yudina have effected a route to several indolo[3,2- 7]carbazoles, such as 175 (equation 2) via a double Fischer indolization [356]. Such compounds are of biological interest because 175 is formed in vivo after the consumption of cruciferous vegetables. It has a strong affinity for the dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) (TCDD) Ah-receptor. Moreover, the 6-formyl derivative 176 binds more strongly to the Ah-receptor than TCDD itself [357, 358]. Saracoglu and Talaz have transformed cyclooctanone into tetrameric indole 177 by stepwise Fischer indolization steps [359]. 

The following sequence of reactions gives cyclooctanone. Propose a structural formula for compound A and a mechanism for its conversion to cyclooctanone. 

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