Ketone, ethyl cyclohexyl

Cyclohexenol, 127 Cyclohexenone, 46 d.y-Cyclohexenones, 257 Cyclohexyldicyclopentylcarbinol, 5 Cyclohexyl ethyl ketone, 131 Cyclohexyl hydroperoxide, 207 Cyclohexylidenemalononitrile, 324 Cyclohexylisonitrile, 122 Cyclohexylmethylcarbinol, 408 Cyclonerodiol, 292... 

Masamune and coworkers studied the deprotonation of 3-pentanone and ethyl cyclohexyl ketone with various bases. These workers confirmed that lithium hexamethyldisilazane gives more ( -isomer than... 

Masamune and coworkers have examined the facial selectivity of the (Z)-lithium enolates of 3-penta-none and ethyl cyclohexyl ketone with a series of P-alkoxy aldehydes having stereocenters at both the a-and p-position (equation 110 Table 18). In the six-mernbered chelate, the methyl and R groups are on the same side of the ring, and it may be seen from the data in Table 18 that the nature of R influences the facial preference of the chiral aldehyde. Another example of this effect is seen in equation (54). 

We studied the hydrogenation of acetophenone, where a great deal of side-reactions and production of intermediaries take place in a three-phase reactor, with liquid batch and gas continuously fed, at constant pressure and temperature. The catalyst is Rhodium (3%) over activated carbon. The solvent is Cyclohexane. Samples are taken at different instants and analysed by gas chromatography. The species for which measures are available are acetophenone, AC, phenyl-ethanol, PE, methyl-cyclohexyl-ketone, ethyl-benzene, EB, ethyl-cyclohexane, cyclohexenyl-ethanol, CNE, methyl-cyclohexenyl-ketone and cyclo-hexyl-ethanol, CE. 

Methylsulfinyl cyclohexyl ketone is prepared by reaction of the reagent (0.08 mole) with 6.24 g (0.04 mole) of ethyl cyclohexanecarboxylate yielding about 7 g of product, mp 62-63° after recrystallization from isopropyl ether. 

The manufacture of the cyclohexyl analog is as follows. Phenyl magnesium bromide was prepared from 48.5 g (0.308 mol) of bromobenzene, 7 g (0,29 mol) of magnesium, and 125 ml of dry ether. To it was added at 5°C over a period of A hour 40 g (0.18 mol) of cyclohexyl (3-(N-piperidyl)-ethyl ketone (BP 115° to 117°C/1 mm) in 125 ml of dry ether. The mixture was allowed slowly to come to room temperature, refluxed for one hour, and then poured into ice containing 80 ml of concentrated hydrochloric acid. Ammonium chloride (100 g) and 200 ml of concentrated ammonium hydroxide were added and the organic layer was separated. After drying and removing the solvent, the residue was distilled under reduced pressure. The base distilled at 158° to 170°C (1 mm) and solidified. Upon recrystallization from methanol it melted at 112° to 113°C. 

To 1,320 parts of methyl isobutyl ketone is added 570 parts of 3-diethylamino-1 -cyclohexyl-1 -phenylpropanol-1 (2 mols) and the mixture is stirred until solution is complete. Then 500 parts (3.2 mols or 60% excess) of ethyl iodide are added. After filtration, the filtrate is diluted with an additional 300 parts of methyl isobutyl ketone and the solution is then heated at the reflux temperature (108°C to 110°C) for 9 hours. After cooling to 0°C, the precipitated solid material is removed by filtration, washed with isopropyl acetate and dried. Approximately 111 parts of product is obtained or a yield of 88.6% based on as-is starting material or 92.5% based on real starting material. 

Ketones such as methyl cyclohexyl ketone 1284 react with DMSO/TCS 14, via their enol form, to give 21% of the chloroketone 1285 a and 63% of the a-methyl mercaptoketone 1286 [70]. Reaction of 1284 with DMSO/MesSiBr (TBS) 16 affords 85% of the bromo compound 1285 b and 12% hexahydrophenacyl bromide 1287 but no 1286 [71]. Whereas reaction of tra s-4-phenyl-3-buten-2-one (benzalacetone) 1288 with DMSO/TCS 14 gives 81% of the sulfonium salt 1289 [70], the y9-dicar-bonyl compound ethyl acetoacetate furnishes 69% of 1290 [70]. In contrast with DMSO/TCS 14, the combination DMSO/TBS 16 effects selective monobromina-tion of y9-dicarbonyl compounds [71] (Scheme 8.28). 

The organosilane reduction of ketones in the presence of alcohols provides an excellent route to unsymmetrical ethers. The reaction of cyclohexanone with ethanol and Et3SiH/TFA gives cyclohexyl ethyl ether in good yield.327,328 The... 

Cyclohexyl ethyl ether [TMSI-catalyzed ketone-unsymmetrical ether reduction], 124... 

METHYL ISOBUTYL KETONE n-PENTYL FORMATE n-BUTYL ACETATE sec-BUTYL ACETATE tert-BUTYL ACETATE ETHYL n-BUTYRATE ETHYL ISOBUTYRATE ISOBUTYL ACETATE n-PROPYL PROPIONATE CYCLOHEXYL PEROXIDE DIACETONE ALCOHOL 2-ETHYL BUTYRIC ACID n-HEXANOIC ACID 2-ETHOXYETHYL ACETATE HYDROXYCAPROIC ACID PARALDEHYDE... 

It has been shown that the lead tetraacetate-mediated 1,2-aryl shift of various meta-substituted / -cyclohexyl aryl ketones, e.g. (10), results in excellent yields of the corresponding rearranged esters (11). A unique reaction, providing 3-hydroxy-2-arylacrylic acid ethyl esters (14), has been observed between aryl aldehydes and ethyl diazoacetate in the presence of the iron Lewis acid [rj — (C5H5)Fe(CO)2(THF)BF4], It appears that the enol esters are formed by an unusual 1,2-aryl shift from a possible intermediate (13), which in turn is formed from the reaction of the iron aldehyde complex (12) with ethyl diazoacetate (see Scheme 4). 

The situation is similar with cyclic boronates, which are prepared by the following procedure. Steroid (10 pmol) and the respective substituted boric acid (10 jumol) are dissolved in ethyl acetate (1 ml) and the mixture is allowed to stand for 5 min at room temperature. Under these conditions, 17,20-diols, 20,21-diols and 17,20,21-triols are converted completely into boronates. Cyclic boronate was mainly produced from 17,21-dihydroxy-20-ketone, but side-products also appeared, the formation of which could be suppressed by adding a 10% excess of the reagent [387—389]. Different substituents on the boron atom, such as methyl, n-butyl, tert.-butyl, cyclohexyl and phenyl, are interesting from the viewpoint of GC—MS application. They are further suitable for converting isolated hydroxyl groups into TMS or acetyl derivatives. 

Methyl-3-[N-(l-phenyl-ethyl)-hydroxyamino]- -methylester E16a, 127 (R-NH-OH + En) Pyridin 3-(Dimethoxy-methyl)-4-(fnmy-3-hydroxy-cyclopentyl)-E7b/2, 483 C-[CH(OR)2]-1,2,4-triazin + 3-OH —1-(CO — CH3) — cyclopentan Pyridin-l-oxid 4-Ethoxy-2-(l-hydroxy-cyclohexyl)- E19d. 605 (H - Li/ -(- Keton) Pymolo l,2-a azepin 6-Ethenyl-5-methoxycarbonyl-3-oxo-(5R, 6S, 9aR )-octa-hy dro-E21b, 1974 l-[CH(OH) —... 

Diorgano tellurium compounds have been reacted with methyl iodide (Vol. IX, p 1076), ethyl iodide ethyl iodoacetate, cyclohexyl iodide , methyl bromide, allyl bromide , benzyl bromide , bromoacetone , bromomethyl phenyl ketone , a-bromocarboxylic acids , a-bromocarboxylic acid esters , methyl chloride, and benzyl chloride . 

Probkm 28.28 Using 9-BBN plus any alkenes and unhalogenated acids or ketones, outline all steps in the synthesis of (a) 2-heptanone (b) 4-methylpentanoic acid (c) 4-methyl-2-hexanone (d) l-cyclohexyl-2-propanone (e) ethyl (trans Z-methylcyclopentyl)acetate (f) l>phenyl-4-methyM-pentanone (g) i-cyclopentyl-33 dimethyl-2-butaBone. 

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