Of diethyl ketone

Ethyl p-phenylethyl ketone. Use 100 g. of pure hydrocinnamic acid and 200 g. (201 -5 ml.) of pure propionic acid. Fractionation of the distillate yields 70 g. of diethyl ketone (b.p. 100-102°), 72 g. of ethyl p-phenyl-ethyl ketone (b.p. 245-249° the pure ketone boils at 248°), and 18 g, of crude di-p-phenylethyl ketone (high b.p. residue). 

The following are examples of the above procedure. A mixture of diethylamine and re-butyl alcohol may be separated by adding sufficient dilute sulphuric acid to neutralise the base steam distillation will remove the alcohol. The amine can be recovered by adding sodium hydroxide to the residue and repeating the distillation. A mixture of diethyl ketone and acetic acid may be treated with sufficient dilute sodium hydroxide solution to transform the acid into sodium acetate and distilling the aqueous mixture. The ketone will pass over in the steam and the non-volatile, stable salt will remain in the flask. Acidification with dilute sulphuric acid hberates acetic acid, which can be isolated by steam distillation or by extraction. 

Another issue of regioselectivity arises with meta-substituted arylhydrazones from which either 4- or 6-substitutcd indoles can be formed. Robinson has tabulated extensive data on this point[9]. A study comparing regioselectivity of cyclization as catalysed by HCl/EtOH and ZnClj was carried out for several m-substituted arylhydrazones of diethyl ketone[10]. The results given in Table 7.1 show some dependence on catalyst but mixtures are obtained under all conditions studied. 

Mass Spectrometry Aldehydes and ketones typically give a prominent molecular ion peak m their mass spectra Aldehydes also exhibit an M— 1 peak A major fragmentation pathway for both aldehydes and ketones leads to formation of acyl cations (acylium ions) by cleavage of an alkyl group from the carbonyl The most intense peak m the mass spectrum of diethyl ketone for example is m z 57 corresponding to loss of ethyl radi cal from the molecular ion... 

Reaction with Selenium Nucleophiles. The reactions of selenium nucleophiles are similar to those of the sulfur nucleophiles selenophosphates can be aminoaLkylated (135). A dihydroselenazine has been obtained by reaction of diethyl ketone, elementary selenium, and ethyleneimine (136). 

As illustrated in Scheme 3 20 and Table 3-5, using 55a or 55b as the chiral auxiliary,, vy -aldol adduct 56 can be obtained with high stereoselectivity via aldol reaction of diethyl ketone with various aldehydes.39... 

British Industrial Biological Research Association BIBRA Toxicity Profile of Diethyl Ketone. Technical Report 173, pp 1. Carshalton, UK, 1988... 

Transformation of diethyl ketone to the corresponding SAMP-hydrazone (144) followed by metalation with LDA and trapping with propyliodide produced the (ZSS)-diastereomer of the product hydrazone (145). This was then cleaved to produce the pheromone (146) in 60% chemical yield with 99.5% enantiomeric excess. 

In an elegant asymmetric synthesis of natural serricornin (148) by Mori et al.164), an overall enantioselective alkylation of diethyl ketone via its SAMP-hydrazone (144) was again the key step. (148) is the sex pheromone of the female cigarette beetle,... 

Figure 4. Variation of formaldehyde and rate of reaction throughout the reaction of 40 mm. of diethyl ketone + 40 mm. of oxygen at 400°C. (1)...

The detection of 1,2-propylene oxide in the products from methyl ethyl ketone combustion is particularly interesting. It parallels the formation of ethylene oxide in acetone combustion (8) and of 1,2-butylene oxide in the combustion of diethyl ketone. Thus, there is apparently a group of isomerization reactions in which carbon monoxide is ejected from the transition state with subsequent closing of the C—C bond. Examination of scale molecular models shows that reactions of this type are, at any rate, plausible geometrically. 

Hydrazones prepared from (S)- l-amino-2-(methoxymethyl)pyrrolidine (242) and acyclic ketones have been shown to undergo deprotonation and alkylation with almost complete asymmetric induction at the a-center (79AG(E)397). The ant alarm pheromone, (+)-(5)-4-methyl-3-heptanone (245), was prepared from the metallated hydrazone of diethyl ketone (243) by alkylation with n-propyl iodide and subsequent cleavage of the crude product via its JV-methyl iodide with acid (Scheme 52). The optical purity of the product was >99%. 

Aliphatic ketones also undergo photoreduction, as evidenced by the facile photoreduction of acetone in cyclohexane341 and in hexane.342 Aromatic ketones are more commonly associated with the reaction because they do not undergo type I cleavages as readily as aliphatic ketones. As already mentioned, photolysis of diethyl ketone... 

Calvert has studied the competing type I and II processes in various -propyl alkyl ketones in the gas phase, and finds that increases and decreases as the alkyl group is changed from methyl through r-butyl,359 as might be expected. Perhaps the most dramatic illustration of the inherent inefficiency of type II photoelimination is provided by the fact that at 100°, where the quantum yield for type I cleavage of diethyl ketone is 1.0, the total quantum yield for disappearance of di- -propyl ketone is only 0.58.359... 

In a 500-ml. round-bottomed flask attached to a modified Dean and Stark constant water separator 1 (Note 1) which is connected to a reflux condenser are placed 67.8 g. (0.60 mole) of ethyl cyanoacetate (Note 2), 56.8 g. (0.66 mole) of diethyl ketone (Note 3), 9.2 g. (0.12 mole) of ammonium acetate, 30 g. (0.48 mole) of glacial acetic acid, and 100 ml. of benzene. The flask is heated in an oil bath at 160-165°, and the water which distils out of the mixture with the refluxing benzene is removed from the separator at intervals. Refluxing is continued for 24 hours (several hours after the separation of water has ceased) (Note 4). 

Fractions of total addition products observed, calculated assuming equal gas chromatographic peak, area responses. b Extrapolated values for infinite pressure. c Small amounts of acetone formed are included. d Perhaps contains small amount, of diethyL ketone. 

To explain these results Bradley et al. (13) postulated that disproportionation of ethyl radicals increased relative to combination when hot ethyl radicals were involved in the process. At higher pressures of ethylene, or neon, the hot radicals were deactivated and C4H10 approached the values observed with thermalized ethyl radicals (for example, in the photolysis of diethyl ketone). 

The use of diethyl ketone and diisopropyl ketone for this reaction also achieved excellent enantiose-lectivity (98-99 % ee). Under the same reaction conditions, (/ )-BINAP (58)/Rh catalyst exhibited somewhat lower enantioselectivity (83-95% ee). 

Figure 9 shows the change of the polarized infrared spectra by adsorption of diethyl ketone. Several bands appear by crystallization especially at 858 cm-. The bands due to diethyl ketone itself are not observed. The essential features of the x-ray diagrams and infrared spectra are the same irrespective of the kinds of solvents. From these results it may be considered that formation of a complex of syndiotactic PMMA and solvent molecules is not reasonable, and the adsorbed molecules contribute to the stabilization of crystallites of syndiotactic PMMA. 

Figure 9. The change of the polarized IR spectra of syndiotactic poly (methyl methacrylate) by adsorption of diethyl ketone (39)...

---