Cyclooctane oxides

Transannular reactions have also been described in cyclooctane series. For example, cyclooctane oxide combines with formic acid to form two glycols by such reaction. 

This novel epoxidation method is not confined to benzylic olefins. The oxidizing solution, which can be made quickly from commercially available F2/N2 mixtures, reacts with cyclooctene at 0 °C in less than a minute to form cyclooctane oxide in 85% yield. Straight chain olefins gave similar results with a full retention of the configuration of the parent alkenes (figure 10). 

Scheme 11.12 Cyclooctane oxidation catalyzed by Ru colloids in biphasic water-organic media.

Fig. 5.1 Time-resolved ATR-IR spectra of cyclooctane oxidation in compressed carbon dioxide showing the region of carbonyl stretching frequencies. (Reproduced by permission of The Royal Society of Chemistry [4]).

Fujimoto and co-workers ° have reported a tandem Michael-intramolecular Corey haykovsky reaction of the five-membered cyclic oxosulfonium ylide 247 with acetates of the MBH adducts in the presence of base, producing cyclo-heptene oxide derivatives 248 as a single stereoisomer. However, in the case of the six-membered oxosulfonium ylide 247, the cyclooctane oxide derivatives 249 were obtained as a mixture of stereoisomers in moderate yields (Scheme 3.95). 

The activity of the liquid phase polyhalogenated metalloporphyrins (Co, Mn, Fe) and supported catalysts (silica, polystyrene) and the cationic metalloporphyrins encapsulated in NaX zeolite are founded to be active for cyclooctane oxidation with molecular into ketone and alcohol with primary ketone formation. At the last case the ration c-one/c-ol is higher than at the use supported on silica and polystyrene catalysts and in fact coincide with results, which are received with the cationic metalloporphyrins in solution. [54]. 

Scheme 2.12 Reaction Mechanism of Cyclooctane Oxidation by N-Hydroxylphthalimide...

Suberic Acid. This acid is not produced commercially at this time. However, small quantities of high purity (98%) can be obtained from chemical supply houses. If a demand developed for suberic acid, the most economical method for its preparation would probably be based on one analogous to that developed for adipic and dodecanedioic acids air oxidation of cyclooctane to a mixture of cyclooctanone and cyclooctanol. This mixture is then further oxidized with nitric acid to give suberic acid (37). 

Srinivasan and Ford [158] reported that epoxidation of cyclooctene using excess H202 was catalyzed by polymolybdate such as [Mo7024]6 tethered on the colloidal polymer with alkylammo-nium cations. Cyclooctene was oxidized to give 1,2-epoxy cyclooctane with >99% selectivity at 90% conversion for 24 h at 313 k ... 

Side reactions that occur with intramolecular cycloaddition, such as linear oligomerization or dimerization of the nitrile oxide, are not very common when shorter chain lengths n < 1) are used due to the entropically favored intramolecular process. A rather unusual result in this regard involves the formation of a fused cyclooctane instead of the less-strained six-membered ring (also fused) in the cycloaddition of the nitrile oxide derived from p-naphthoquinone (Scheme 6.43). This result is consistent with the effect of electron-withdrawal in the enedione part, leading to increased reactivity (247), and also reflects the known sluggishness of cyclohexenes towards nitrile oxides (cf. Section 6.2.1.2). 

Since the question of the necessary conditions for isomerization of nitroso-cyclohexane to cyclohexanone oxime is of considerable commercial importance, it has been shown that this tautomerization is favored by the presence of gaseous hydrogen chloride, particularly at a wavelength of 300 mp. [57]. When cyclohexane is saturated with hydrogen chloride, treated with nitric oxide, and exposed to a source of ultraviolet radiation, the oxime forms along with a trace of 1-chloro-l-nitrosocyclohexane [58]. Cyclooctane seems to form the corresponding oxime and the chloronitroso compound, but under no circumstances nitrosocyclooctane [58]. 

Likewise, polycyclic derivatives of bicyclo[4.2.0]octane-l,6-diol were oxidized by periodate to give derivatives of cyclooctane-1,4-dione.37,157... 

Attempts to prepare DPT by oxidation of Din itrosoendomethy lenetetraaza cyclooctane did not succeed (Ref 7, p 220)... 

A chloride-bridged structure has been proposed for the 1 1 adduct, [HgCl2(btaH)]2 (172). Mercury(II) benzotriazolate, Hg(bta)2, has been obtained from mercury(II) perchlorate, benzotriazole, and triethyl-amine in ethanol (172), and from mercuric oxide and benzotriazole (158). Mercuric acetate and chloride react with benzotriazole to form mixed mercury(II) salts, HgX(Ka) (X = MeC02 or Cl) (139). A dimeric structure (Fig. 13) with T-shaped coordination at mercury has been determined by X-ray diffraction methods (203) for the methyl derivative Hg(Me)(bta) (172). Cyclooctane-1,2-dione dihydrazide reacts with HgO... 

Fullerene, Cgo, undergoes photochemical 2 + 2-cycloaddition with /V,A-diethyl-4-methylpent-3-en-l-yn-l-amine to produce the stable Cgo-fused cyclobutenamine that is photo-oxidized to the dihydrofullerenone amide in high yield.15 The photochemical 2 + 2-cycloaddition of arylalkenes with Cgo has been shown to occur by a two-step mechanism involving the formation of a dipolar or diradical intermediate in the rate-determining step.16 The 2 + 2-photo-cycloaddition of cis- and irons-1 -(/j-methoxyphen-yl)-l-propene to C6o produces only trans-2 + 2-adduct. This is consistent with a two-step mechanism.17 The 2 + 2-photo-cycloaddition of cyclic 1,3-diones to Cgo results in the formation of two furanylfullerenes, one chiral and the other achiral. None of the expected De Mayo cyclooctane-1,3-dione addition products were formed.18... 

An oven-dried 300-ml flask, equipped with a side-arm fitted with a silicone rubber septum, a magnetic stirrer bar, and a reflux condenser connected to a mercury bubbler, is cooled to room temperature under a stream of dry nitrogen. Tetrahydrofuran (20 ml) is introduced, followed by 7.1 g (25 mmol) of cyclooctyl tosylate (1). The mixture is cooled to 0 °C (ice bath). To this stirred solution, lithium triethylborohydride (Section 4.2.49, p. 448) [33.3 ml (50 mmol) of a 1.5 m solution in tetrahydrofuran] is added, and the ice bath removed. The mixture is stirred for 2 hours (c. 25 °C). Excess hydride is decomposed with water. The organoborane is oxidised with 20 ml of 3 m sodium hydroxide solution and 20 ml of 30 per cent hydrogen peroxide [(2) and (3)]. Then the tetrahydrofuran layer is separated. The aqueous layer is extracted with 2 x 20 ml portions of pentane. The combined organic extracts are washed with 4 x 15 ml portions of water to remove ethanol produced in the oxidation. The organic extract is dried (MgS04) and volatile solvents removed by distillation (2). Distillation of the residue yields 2.27 g (81%) of cyclooctane as a colourless liquid, b.p. 142-146 °C, Wq0 1.4630. 

These iron porphyrin derivatives selectively catalyzed cyclohexane hydroxidation, where (FeTNMCPP)Cl displayed the higher stability. Cyclooctane epoxidation on the same mimic proceeded with multiple oxidant addition. 

This epoxide has been found to be particularly useful in the laboratory in the large-scale preparation of frarty-cyclooctene using the procedure of Whitham.14 trans-Cyclooctane- 1,2-diol is obtained from cis-cyclooctene oxide on treatment with sodium acetate in acetic acid and alkaline hydrolysis of the intermediate trans-2-acetoxycyclooctanol. The trans diol is converted to its benzal-dehyde acetal, which on treatment with butyllithium affords trans-cyclooctene in a stereospecific manner. 

When a,o -dithiols are reacted with dibutyltin oxide, stannathianes are formed and used as templates for the preparation of thialactones <2004JOC8550> (Scheme 3). The example template shown in Scheme 3 is easily obtained, when dibutyltin oxide 9 is suspended in toluene and heated to reflux. Then 3-thiapentane-l,5-dithiol 10 dissolved in toluene is added dropwise and the resulting mixture is refluxed for 24 h. After cooling to 25 °C the product is concentrated by vacuum and the residue is purified by chromatography to give 2,2-dibutyl-2-stannatrithia-cyclooctane 11 in 83% yield. When 11 is treated with pimeloyl dichloride 12, two thialactones are obtained 13 (1 1 ratio product, 63%), and 14 (2 2 ratio product, 20%). 

Apart from the well-known oxidative additions to Ir1, hydrogen can also be added to Ir111. In the case of (21-VIII) the reaction proceeds at room temperature the resulting Irvtetrahydride reductively eliminates H2 only on heating above 130°C and is a highly active catalyst for the transfer dehydrogenation of cyclooctane.28... 

---