Ethers, ketoxime methyl

Methyl n-amyl carbinol. 247, 254 Methyl n-amyl ketone, 482 Methylaniline (mono), pure, from commercial methylaniline, 562, 570 P-Methylanthraquinone, 728, 740 Methyl benzoate, 780, 781 p-Methyl benzyl alcohol, 811,812 Methyl benzyl ketone, 727, 735 Methyl y-bromocrotonate, 926, 927 2-Methyl-2-butene, 239 Methyl n-butyl carbinol, 247,255 Methyl n-butyl ether, 314 Methyl n-butyl ketone, 475, 481 4-Methylcarbostyril, 855 p-Methylcinnamic acid, 719 4-Methylcoumarin, 853, 854 Methyl crotonate, 926, 927 Methylethylacetic acid, 354, 358 Methylethylethynyl carbinol, 468 Methyl ethyl ketone, 335, 336 purification of, 172 Methyl n-hexyl ether, 314 Methyl n-hexyl ketone, 335, 336 Methyl n-hexyl ketoxime, 348 Methyl hydrogen adipate, 938 Methyl hydrogen sebacate, 938,939 4-Methyl-7-hydroxycoumarin, 834 Methyl iodide, 287 Methyl isopropyl carbinol, 247,255 Methyl 4-keto-octanoate, 936... 

Anionic 1,4-silyl migrations of O-trialkylsilyl methyl ketoximes (268) were found to give o -trialkylsilyl ketoximes 269 after hydrolysis (equation 167). Intramolecularity of this migration was confirmed by crossover experiments. Upon heating 269 at 100 °C, a reverse migration to 268 took place. The reaction appeared to be limited to silyl ethers of methyl ketoximes having the (E)-configuration413. 

Unsymmetrical ketoximes or ketoxime methyl ethers undergo rapid deprotonation to give syn dianions or monoanions, which react regioselectively with electrophilic reagents. ° ° Axial alkylation is observed in conformationally rigid systems. Aldoximes can also be converted to their dianions and alkylated in high yields. ... 

The reduction of ketoxime ethers by borane in the presence of (—)-norephedrine yields (S)-amines from a/ i-kctoximcs and (/ )-isomers from. s i/ -ketoximes, e.g. from phenyl-4-tolyl-methyl ketoxime methyl ether40. 

Ketoximes are known to behave in some cases as C-H acids, for example, they are metalated across the a-CHj and CH2 groups (Scheme 1.196) [278,281,401,402], RegioselecUve deprotonation of ketoxime methyl ethers, namely, proton abstraction from the cis-position relative to the methoxy group, has been noted (Scheme 1.197) [278]. 

Place 80 g, of hydroxylamine sulphate (or 68-5 g. of the hydrochloride), 25 g. of hydrated sodium acetate, and 100 ml. of water in a 500 ml. flask fitted with a stirrer and a reflux water-condenser, and heat the stirred solution to 55-60°. Run in 35 g (42 nil,) of -hexyl methyl ketone, and continue the heating and vigorous stirring for ij hours. (The mixture can conveniently be set aside overnight after this stage.) Extract the oily oxime from the cold mixture twice with ether. Wash the united ethereal extract once with a small quantity of water, and dry it with sodium sulphate. Then distil off the ether from the filtered extract, preferably using a distillation flask of type shown in Fig. 41 (p. 65) and of ca, 50 ml, capacity, the extract being run in as fast as the ether distils, and then fractionally distil the oxime at water-pump pressure. Collect the liquid ketoxime, b.p. 110-111713 mm. Yield, 30-32 g. 

An early approach to the formation of chiral amines by nonenzymatic asymmetric synthesis was the reduction of prochiral ketoximes and their O-tetrahydropyranyl and O-methyl derivatives with lithium aluminum hydride-3-0-benzyl-1,2-0,0-cyclohexylidene-a-D-glucofuranose complex (16)33 in ether and prochiral ketoximes... 

Enehydroxylamines (102) are invoked as intermediates in the rearrangement of O-vinyl, acyl or aryl oximes (101) (equation 31). Varlamov and coworkers demonstrated that the heterocyclization of ketoximes (103) with acetylene in snper basic medium and in the presence of metal hydroxides proceeds by a [3,3]-sigmatropic rearrangement of the enehydroxylamine 105 of the corresponding oxime vinyl ethers 104 (equation 32). The unreactivity of 3-methyl-2-azabicyclo[3.3.1]nonan-9-one oxime (106) in the same reaction conditions was explained by its inability to isomerize to the corresponding enehydroxylamine. 

Sheradsky has found that the hydroxyl function of a ketoxime such as acetophenone oxime can be made to react with DMAD when the reaction is carried out in methanol with a basic catalyst, to give mixture of the fumarate and maleate isomers (164) in the ratio 2 1. This mixture on heating undergoes a hetero-Cope rearrangement followed by cyclization and dehydration to give dimethyl 5-phenylpyrrole-2,3-dicarboxylate (168) (Scheme 25). Similarly, Heindel and Chun have reported that vinyl ether adducts (171), obtained by the condensation of arylamide oximes with DMAD, get thermally converted into oxa-diazolines (172) or imidazolinones (174), depending on the reaction conditions. A similar reaction occurs with aromatic amidoxime-methyl propiolate adducts to give imidazoles (170) (Scheme 26). 1,2,4-Dioxazoles have been reported to be formed in the reaction of hydrox-amic acids with DMAD. - ... 

Methyl 2-pyridyl ketoxime. A solution of 2-acetylpyridine (3, Acros, 27.2 g, 0.225 mole) and hydroxylamine hydrochloride (18.0 g, 0.259 mole) in 100 mL of pyridine is stirred magnetically and heated to reflux in a 250-mL, round-bottomed flask fitted with a water-cooled reflux condenser for 6 h. After removing the solvent on a rotary evaporator, 400 mL of HzO is added, resulting in precipitation of the oxime in the form of a white precipitate which is isolated by vacuum filtration. The filtrate is extracted three times with 100 mL of ether. The white solid is dissolved in ether and combined with the extracts, and then dried with Na2S04. The solvent is evaporated using a rotary evaporator. The crude product (30.0 g, 97%) is used directly in the next step without further purification. 

The conversion of steroidal ketoximes and the derived oxime acetates, benzoates and methyl and benzyl ethers into enamides was described by Barton and coworkers621,622. For example, the oxime of 5-a-cholestan-3-one (147) forms with acetic anhydride in pyridine the enamide 148 which, under the reaction conditions, is acetylated on nitrogen to form the enimide 149. Chromatography on alumina cleaves the enimide to the enamide. 

Enantioselective Reduction of Imines and Ketoxime O-Ethers. In addition to the reduction of prochiral ketones, chiral oxazaborolidines have been employed as enantioselective reagents and catalysts for the reduction of imines (eq 11) and ketoxime O-ethers (eq 12) - to give chiral amines. It is interesting to note that the enantioselectivity for the reduction of ketoxime O-ethers is opposite that of ketones and imines. For more information, see 2-Amino-3-methyl-l,l-diphenyl-I-butanol. 

Ketoxime ethers derived from structures (146)and (147) where R = H, methyl, propar-gyl, or C-alkyl-substituted propargyl showed Mg agonist activity in a rat aorta preparation, but no M2 agonist activity (185). 

CLEAVAGE OF ETHERS Aluminum chloride. Boron tribromide. Bromine. Dimethylformamide. Methylmagnesium iodide. Triphenylphosphine dibromide. a-GLYCOLS Silver iododibenzoate KETOXIMES Chromous acetate METHYL ESTERS Lithium n-propyl mercaptide. 

Methyl ethyl carbinol. See 2-Butanol Methylethylcetoxime. See Methyl ethyl ketoxime 1-Methyl ethylene carbonate. See Propylene carbonate Methyl ethylene glycol. See Propylene glycol Methyl ethylene oxide. See Propylene oxide Methyl ethyl glycol. See Propylene glycol 1-Methylethyl hexandecanoate. See Isopropyl palmitate 1-Methylethyl 2-hydroxypropanoate. See Isopropyl lactate 4,4 -(1-Methylethylidene) biscyclohexanol. See Bisphenol A, hydrogenated 4,4 -(1-Methylethylidene) bisphenol. See Bisphenol A 2,2 -((1-Methylethylidene) bis (4,1-phenyleneoxymethylene)) bisoxirane. See Bisphenol A diglycidyl ether... 

MEHQ. See Hydroquinone monomethyl ether MEK (INCI). See Methyl ethyl ketone MEKO. See Methyl ethyl ketoxime Mekon White. See Microcrystalline wax MEK oxime. See Methyl ethyl ketoxime MEKP MEK peroxide. See Methyl ethyl ketone... 

The benzyl ether of diethyl ketoxime (W-171, R =C2Hs) and benzylmalonyl chloride in benzene give 3-benzyl-l-benzyloxy-6-ethyl4-hydroxy-5-methyl-2-... 

Methyl ethyl ketoxime (2-Butanone oxime or Ethyl methyl ketone oxime) Methyl eugenol (Methyleugenyl ether)... 

Iron pentacarbonyl can regenerate carbonyl compounds from oximes under aprotic conditions (Alper and Edward, 1967). The presence of boron trifluoride etherate affords products in 55-81% yields although the reaction can take place—sometimes in reduced yields—in the absence of the Lewis acid (XXXIII - XXXIV) (Alper and Edward, 1969). The intermediate was isolated using the sterically hindered reactant, methyl mesityl ketoxime (Dondoni and Barbaro, 1975). 

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