Cyclooctanone 2-

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). 

Cyclooctanone [502-49-8] M 126.2, m 42". Purified by sublimation after drying with Linde type 13X molecular sieves. 

Experimental evidence, obtained in protonation (3,6), acylation (1,4), and alkylation (1,4,7-9) reactions, always indicates a concurrence between electrophilic attack on the nitrogen atom and the -carbon atom in the enamine. Concerning the nucleophilic reactivity of the j3-carbon atom in enamines, Opitz and Griesinger (10) observed, in a study of salt formation, the following series of reactivities of the amine and carbonyl components pyrrolidine and hexamethylene imine s> piperidine > morpholine > cthyl-butylamine cyclopentanone s> cycloheptanone cyclooctanone > cyclohexanone monosubstituted acetaldehyde > disubstituted acetaldehyde. 

The lifetime of the diazomethane adduct is not known, but it must be of sufficient length that carbon can compete with nitrogen in participation as a nitrogen molecule leaves (24,109). The reaction of 66 with diazoethane yields 72, the normal adduct, and 73, the product from ring expansion. The structure of 73 was determined by hydrolysis to 2-methylcyclo-heptanone. In a similar reaction 74 yields 67 directly without isolation of 66. A similar ring expansion has been observed for cyclooctanone derivatives (16). 

The reaction of methyl propiolate (82) with acyclic enamines produces acyclic dienamines (100), as was the case with dimethyl acetylenedicarboxylate, and the treatment of the pyrrolidine enamines of cycloheptanone, cyclooctanone, cycloundecanone, and cyclododecanone with methyl propiolate results in ring enlargement products (100,101). When the enamines of cyclohexanone are allowed to react with methyl propiolate, rather anomalous products are formed (100). The pyrrolidine enamine of cyclopentanone forms stable 1,2-cycloaddition adduct 83 with methyl propiolate (82). Adduct 83 rearranges to the simple alkylation product 84 upon standing at room temperature, and heating 83 to about 90° causes ring expansion to 85 (97,100). 

A fundamental problem in the alkylation of enamines, which is inherent in the bidentate system, is the competition between the desired carbon alkylation and attack at the nitrogen. With unactivated alkyl halides (3,267), this becomes especially serious with the enamines derived fromcycloheptan-one, cyclooctanone, cyclononanone, and enamines derived from aldehydes. Increasing amounts of carbon alkylation are found with the more reactive allyl and benzyl halides (268-273). However, with allyl halides one also observes increasing amounts of dialkylation of enamines. 

After most of the mineral oil has been removed, 400 ml. of benzene is added to the sodium hydride, followed by 71 g. (0.6 mole) of diethyl carbonate (Note 5). This mixture is heated to reflux, and a solution of 38 g. (0.3 mole) of cyclooctanone (Note 6) in 100 ml. of benzene is added drop wise from the dropping funnel over a period of 3-4 hours. After the addition is complete, this mixture is allowed to reflux until the evolution of hydrogen ceases (15-20 minutes). 

The cyclooctanone was obtained from the Aldrich Chemical Co. and was utilized as received. 

The reaction of cyclooctanone with diethyl oxalate, followed by decarbonylation of the resulting glyoxylate, has been reported to yield 32% of 2-carbethoxycyclooctanone.2 The reaction of cyclooctanone with sodium amide in ether, followed by the... 

Cyclooctanol, oxidation by chromium trioxide to cyclooctanone, 48, 29 Cyclooctanone, 46, 28... 

Cyclooctanone, condensation with diethyl carbonate, 47, 20 Cyclopentadiene, adduct formation with 1,2,3-benzothiadiazole 1,1-diox-ide, 47, 8... 

Silylation of the 2-qfclohexanone phenylsulfoxide 1213 with the O-silylketene-acetal 1214 in the presence of Znl2 gives 75% of the Sila-Pummerer product 1215, whereas the 2-cyclooctanone phenylsulfoxide 1216 affords a ca. 1 1 mixture of the Sila-Pummerer products 1217 and the olefin 1218 [31] (Scheme 8.12). 

Reaction of cyclic ketones with diazomethane leads to ring enlargement. Thus cyclohexanone (I) (1 mol) and diazomethane (1 mol) give c/oheptanone (II) in about 60 per cent, yield together with a little epoxide (III) as by product and some cyclooctanone (IV) resulting from further reaction of cycloheptanone with dlazomethane. ... 

However, cyclopentanone 3-109 with a cis orientation of the iodoalkane group and the alkyne moiety was converted into the fused cyclooctanone 3-110 in 82% yield (Scheme 3.28). In contrast, the corresponding trans-isomer only underwent 1,5-hydrogen transfer, leading to a dehalogenated starting material. 

Cyclooctanone from Aldrich Chemical Co., methyl pro-piolate from Farchan Research Laboratories, and pyrrolidine from Eastman Organic Chemicals were used as received. 

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