Cycloheptanone, acidity

Enamines formed in this way may be distilled or used in situ. The ease of formation of the enamine depends on the structure of the secondary amine as well as the structure of the ketone. Thus pyrrolidine reacts faster than morpholine or piperidine, as expected from a rate-controlling transition state with imonium character. Six-membered ring ketones without a substituents form pyrrolidine enamines even at room temperature in methanol (20), and morpholine enamines are generated in cold acetic acid (21), but a-alkylcyclohexanones, cycloheptanone, and linear ketones react less readily. In such examples acid catalysis with p-toluenesulfonic acid or... 

Cycloheptanone Cyanoacetic acid methyl ester Ethyl bromide Hydrogen chloride... 

A1( -octalone, 45, 80 N-nitioso-N-phenylglycine to N-phenylsydnone, 45, 96 Cyclobutanecarboxylic acid, reaction with hydrazoic acid, 47, 28 Cyclobutene, 1,2,3,4-tetrasiethyl-3,-4-dichloro-, 46, 34 reactions of, 46, 36 Cyclobutylamine, 47, 28 Cyclobutyl isocyanide, 46, 77 Cycloheptanone, 45, 31... 

Pimelic Acid (Heptanedioic Acid or 1,5-Pentane-dicarboxytlc Acid). HOOC.(CH2)s.COOH mw 160.17 white prisms mp 106° bp 272° at 100mm (subl), and 212° at 10mm d 1.329 g/cc at 15°. Sol in w, ethanol, eth and hot benz. Prepn is by oxidn of cycloheptanone, capric acid or oleic acid treatment of salicylic acid with Na in amyl ale, or by decarboxylating 1,1,5,5-pentanetetracarboxylic acid with heat Pimelic acid has been combined with cis and trans-, 4-cyclohexanediol to give polyesters, and with m-xylene-ce,ol -diamine or poly-methylenediamines to form polyamides. With diperoxides, the acid forms resins. It is also used as the parent compd to form the expls presented below... 

The retentive power of graphite towards adipic acid and the catalytic effect of the magnetite, especially present in A, are obvious. TEM examinations of a graphite A sample before and after reaction showed that crystallites of Fe304 appeared to be smaller after the reaction. However, the same graphite sample was reused for three successive reactions without significant loss in yield. When applied to the synthesis of other cyclic ketones (Scheme 7.14), less volatile than 74, it was observed that pressure had an effect on the recovery of product (Tab. 7.9, entries 3 and 4). A slightly reduced pressure (300 mm Hg) was necessary to obtain 3-methylcyclopentanone (75) or cyclohexanone (76) in convenient yield (Tab. 7.9, entries 4 and 5). For the cycliza-tion of suberic acid (73), a less favorable structure, the yield in cycloheptanone (77) remained low (Tab. 7.9, entry 6). 

Cyclooctanone has been prepared by distilling the calcium and thorium salts of azelaic acid, by heating azelaic acid with barium oxide in the presence of iron, by the action of nitrous acid on l-(aminomethyl)-cycloheptanol, by Dieckman cyclization of azelaic acid dimethyl ester and diethyl ester, and by ring expansion of cycloheptanone with diazomethane. ... 

The lactam (2) is obtained in 87% yield by treating cycloheptanone with sodium azide and concentrated hydrochloric acid (54JA2317). Beckmann rearrangement of cycloheptanone oxime with concentrated sulfuric acid gives (2) in 88% yield (58JA1510). Alternatively, the ketone gives (2) directly by reaction with hydroxylamine sulfonate in 95% formic acid (79S537). 

The submitters state that the yields of cycloheptanone obtained from 60- to 700-g. quantities of the crude acetic acid salt of... 

Small quantities of cycloheptanone are prepared more conveniently by the diazomethane method4 or by dry distillation of suberic acid salts 6-7 or suberic acid admixed with iron filings and barium hydroxide.8... 

In the presence of proton and/or Lewis acid and strong nucleophiles bicyclo[3.2.0]heptan-6-ones are converted to 3-substituted cycloheptanones (Table 15). Bicyclo[3.2.0]heptan-6-ones rearrange to give 3-iodocycloheptanones on treatment with iodotrimethylsilane. Zinc(II) iodide or mercury(II) halides as catalysts enhance the rate and the selectivity of the reaction.31 If a second, enolizable carbonyl group is present, an intramolecular alkylation may follow the ring enlargement under these reaction conditions.32 Consecutive treatment with tributyltin hydride/ 2,2 -azobisisobutyronitrile affords reduced, iodo-free cycloheptanones, whilst treatment with l,8-diazabicyclo[5.4.0]undecene yields cycloheptenones.33 Similarly, benzenethiol adds to the central bond of bicyclo[3.2.0]heptan-6-ones in the presence of zinc(II) chloride and hydrochloric acid under anhydrous conditions to form 3-(phenylsulfanyl)cycloheptanones.34... 

Table 15. Cycloheptanones by Lewis Acid Promoted Cleavage of Bicyclo[3.2.0]heptan-6-ones...

The conversion of a cycloheptanone to a bicyclo[5.3.0]decane derivative can be effected through ring opening of an intermediate furfurylidene derivative (57JA6023). Thus, condensation of 2-methylcycloheptanone with furfuraldehyde in the presence of sodium methoxide gave (61). On heating with concentrated hydrochloric acid in ethyl alcohol, the ketovaleric acid (62) was produced which on aldolization furnished the bicyclic ketone (63) in 17% overall yield (Scheme 15). 

Catalytic rearrangement of 2-(l-hexynyl)-7-(dichloromethylene)oxepane, promoted by the reaction of Co2(CO)g with the triple bond and catalyzed by Lewis acid (BF3-OEt2 or TiCU), afforded the corresponding Co2(CO)6 complex of 2,2-dichloro-3-(l-hexynyl)cycloheptanone <2002AGE2584>. 

Rather high (80-90%) yields of dihydrodiazepines are observed when the reaction is carried out on a MgO surface in the presence of phosphorus chlor-oxide [17]. In this manner some dihydrobezodiazepine derivatives 78 and 80 with alkyl substituents are obtained (Scheme 4.25). It should be noted that high product yields are also observed in the reactions of o-PDA with cyclic ketones (e.g., cyclopentanone, cyclohexanone and cycloheptanone), which is not typical of routine acid catalysis [14, 99]. 

DIETHYL ESTER, 33, 23 Cycloheptanone, 34, 19, 24 sodium bisulfite adduct, 34, 25 Cyclohexane, iodo-, 31, 66 A1, -Cyclohexaneacetic acid, a-CYANO-, 31, 25, 26... 

---