Methyl ethyl ketone cyanohydrin

Methyl ethyl ketone cyanohydrin, 20,44 N-Methylformanilide, 20, 11, 66 Methyl- 8-formylpropionate, 21, 88 a-Methylglucoside, 20, 99... 

The simplest aldehyde cyanohydrin, glycolonitrile, has been prepared by a cyanohydrin interchange between formalin and methyl ethyl ketone cyanohydrin. ... 

Methyl ethyl ketone cyanohydrin, 20,44 N-Methyltormanilide, 20, 11, 66 o-Methylformanilide, 23, 43 Methyl /3-formylpropionate, 21, 88 a-Methylglucoside, 20, 99 /3-Meihylglutaric acid, 23, 60 Methyl hydrogen adipate, 26, 52 Methyl hydrogen succinate, 25, 19 4-MEIHYL-7-HYDROXY-8-ACETYLCOU1IA-RIN, 21, 25... 

Ethylene Cyanohydrin. This cyanohydrin, also known as hydracrylonitnle or glycocyanohydrin [109-78-4] is a straw-colored Hquid miscible with water, acetone, methyl ethyl ketone, and ethanol, and is insoluble in benzene, carbon disulfide, and carbon tetrachloride. Ethylene cyanohydrin differs from the other cyanohydrins discussed here in that it is a P-cyanohydrin. It is formed by the reaction of ethylene oxide with hydrogen cyanide. 

Ethylene Cyanohydrin or /3-Hydroxypropio-nitrile, HO.CH8.CH2.CN mw 71.08, N 19.71% poisonous straw-colored Uq, sp gr 1.0404 at 25°/4, fr p -46°, bp 227-28°(dec), vapor pressure 20mm at 117 miscible with w, acet, ethanol, chlf, methyl-ethyl ketone si sol in eth insol in benz, CC14 naphtha. It can be prepd by interaction of ethylene oxide with... 

Poly(styrene-co-acrylonitrile) samples (SAN) have been fractionated through methanol-acetone or methanol-dichloromethane mixtures of stepwise-altered composition 108) through methanol/dichloromethane, n-hexane/dichloromethane, or methanol/acetone gradients109), cyclohexane/methyl ethyl ketone gradients 110), or (toluene — 1-propanol 50 50)/dimethyl formamide gradients111. Mixtures of ethylene cyanohydrin — ethylene carbonate 112) or cyclohexane — methyl ethyl ketone 113 have also been used for the separation of SAN copolymers. Both the latter systems as well as the n-hexane/dichloromethane gradient109) had the efficacy of fractionating SAN copolymers by composition. 

The cyanohydrin synthesis of a-hydroxy acids is very often carried out without isolation or purification of the cyanohydrins. The various techniques for the preparation of the cyanohydrins are discussed elsewhere (method 390). Hydrolysis to the a-hydroxy acids is usually effected by heating with concentrated hydrochloric acid. Excellent directions are given for mandelic acid (52% over-all from benzaldehyde), a-methyl-a-hydroxybutyric acid (65% from methyl ethyl ketone), and eighteen dialkyl- and alkylphenyl-glycolic acids (60-80%). Sodium hydroxide solution is used in the preparation of /S-hydroxypropionic acid from the /S-hydroxy nitrile (80%). ... 

Methyl benzyl ketone cyanohydrin and ethyl mercaptan in anhydrous benzene or benzene-ether ice-cooled, satd. with HCl, kept 15 days in a refrigerator, the resulting crude thioimidoester hydrochloride treated with water, and steam-distilled product. Y 80.2%. F. e. s. W.E. Elias, Can. J. Chem. 48, 3662 (1970). 

Table 3. Synthesis of (R)-ketone cyanohydrins by Prunus amygdalus oxynitrilase catalysed addition of HCN to A methyl ketones (RCOCH3) and B ethyl ketones (RCOCHjCH,)...

Methyl ketones are transformed into cyanohydrins [1559], while ethyl ketones are impeded by low yields [1560]. 

Most of the aforementioned hydroxynitrile lyases are able to catalyze the addition of HCN to ketones to furnish (R)- or (S)-ketone cyanohydrins (Table 10.3). Using PflHnL as catalyst, alkyl methyl ketones gave moderate yields and high optical purities, whereas with alkyl ethyl ketones the)fields and optical purities were lower [39,42]. The substrate scope has been extended to methyl phenyl ketones, cyclic, bicyclic, heterocyclic, as well as silicon-containing compounds [16]. Concerning (S)-ketone cyanohydrins, excellent results were achieved with aliphatic and aromatic ketones, for example, acetophenone cyanohydrin, using (S)-HbHnL (40% conversion, 99% ee.. Table 10.3) or (S)-MeHnL (87% conversion, 98% ee... 

The hydroxynitrile lyase (HNL)-catalysed cyanohydrin reaction is a useful method to synthesize enantiopure a-hydroxy nitriles and the corresponding a-hydroxy acids. However, small ketones, such as 2-butanone, are converted with low selectivities, due to the poor discrimination between methyl and ethyl. ... 

The Cs-phosphonium ester salts 95 + 99 and the Cs-phosphonate ester 100 (Scheme 11), as well as their corresponding methyl esters, are key building blocks for the manufacture of various polyenecarboxylic acid esters for use in the carotenoid field [34-36]. An efficient route uses as an intermediate 2-hydroxy-2-methylbut-3-enoic acid ethyl ester (101) [37,38], which can be prepared from methylvinyl ketone (102) by acidic ethanolysis of the cyanohydrin 103, prepared by reaction of 102 with HCN (104). Reaction of 101 with thionyl chloride under reflux conditions led to a 76% yield of distilled 4-chloro-2-methyl-but-2-enoic acid ethyl ester (105), from which the phosphonium chloride 98 was obtained in good yield [36]. 

---