Reaction of, with acetaldehyde

Hexylmagnesium bromide, reaction of with acetaldehyde, 555 with ethylene oxide, 588 1-Hexyne, 556... 

Reactions with Ammonia and Amines. Acetaldehyde readily adds ammonia to form acetaldehyde—ammonia. Diethyl amine [109-87-7] is obtained when acetaldehyde is added to a saturated aqueous or alcohoHc solution of ammonia and the mixture is heated to 50—75°C in the presence of a nickel catalyst and hydrogen at 1.2 MPa (12 atm). Pyridine [110-86-1] and pyridine derivatives are made from paraldehyde and aqueous ammonia in the presence of a catalyst at elevated temperatures (62) acetaldehyde may also be used but the yields of pyridine are generally lower than when paraldehyde is the starting material. The vapor-phase reaction of formaldehyde, acetaldehyde, and ammonia at 360°C over oxide catalyst was studied a 49% yield of pyridine and picolines was obtained using an activated siHca—alumina catalyst (63). Brown polymers result when acetaldehyde reacts with ammonia or amines at a pH of 6—7 and temperature of 3—25°C (64). Primary amines and acetaldehyde condense to give Schiff bases CH2CH=NR. The Schiff base reverts to the starting materials in the presence of acids. 

On the basis of studies of the reactions of formaldehyde, acetaldehyde and butyraldehyde with ethylzinc diphenylamide as a model catalyst of moderate effectiveness, Van der Kerk [279] revealed the mechanism of aldehyde coordination polymerisation by means of organozinc catalysts ... 

Compound (1) and 2-methyl-1//-pyrrolo[2,3-Z>]pyridine (87) have been prepared by a heterogeneous catalyzed Fischer reaction. A cyclization reaction occurred with acetaldehyde and acetone 2-pyridylhydrazones in the presence of y-alumina and fluorinated aluminum oxide (Equation (20)). In addition to the desired pyrrolopyridine products, 2-aminopyridine (88) and a triazine derivative (89) were also formed. Use of the fluorinated aluminum oxide maximized formation of the desired products <72CHE594, 72CHE1037). 

Razumov, A.L, Sokolov, M.P, Liorber, B.G., Zykova, T.V, Salakhutdinov, R.A., and Uimancheeva, G.V., Reactivity and structure of phosphorylated carbonyl compounds. Part 14. Study of the reaction of phosphorylated acetaldehydes with P-aminocarbonyl compounds, Zh. Obshch. Khim., 47, 2717, 1977 J. Gen. Chem. USSR (Engl. Transl.), 47, 2474, 1977. 

Fig. 6.33. Views of the 3-2IG transition-state structure for the aldol reaction of lithium acetaldehyde enolate with formaldehyde...

We said that a solution of acetaldehyde in methanol contains a new compound a hemiacetal. We ve also said that the rate of formation of hemiacetals is increased by adding an acid (or a base) catalyst to the alcohol plus aldehyde mixture. But, if we add catalytic acid to our acetaldehyde-methanol mixture, we find not only that the rate of reaction of the acetaldehyde with the methanol increases, but also that a different product is formed. This product is an acetal the hemiacetal is half-way there. 

Diacetyl, butane-2,3-dione CH3-CO-CO-CH3, a diketone produced as a byproduct of carbohydrate degradation, m.p. -3°C, b.p. 88.8 °C.D. is a component of butter aroma, and has been found in many biological materials. It is produced by dehydrogenation from acetoin, the decarboxylation product of pyruvate. In microorganisms D. is also produced by reaction of active acetaldehyde with acetyl-CoA. Little is known about the further metabolism of D.It is used as an aroma carrier in the food industry. 

Ala, A). Thus, reaction of ethanal (acetaldehyde, CH3CHO) with ammonium chloride (NH4Cl(aq)) and HCN leads to the production of racemic 2-aminopropionitrile, which, on hydrolysis with aqueous HCI, produces racemic alanine (Ala, A). 

Zinc and Mercury.—As in previous years, reports of new transformations and methodologies involving zinc have been at a low level. A useful high-yielding conversion has been published, however, of allylic thioethers such as (84) into homoallylic thioethers (85). The initial ylide formation with a homogeneous solution of diethylzinc and methylene (R = H) or ethylidene (R = Me) iodide is followed by a 2,3-sigmatropic rearran ment to the observed products, and the poor yields found in previous experiments can be avoided by quenching the reaction mixture with acetaldehyde. Conventional Simmons-Smith cyclo-propanation of these compounds fails, as does the cyclopropanation of cyclohexene in the presence of various thioethers. 

The reaction of trichloro-acetaldehyde (chloral) with phenols under base catalysis leads to p-hydroxyaryltrichloroethanols together with some o-isomer. The corresponding aromatic hydroxy aldehydes are produced after reaction with aqueous alkali or boiling in... 

Another important piece of evidence for the rate-limiting nature of the migratory insertion step is the fact that the Hammett p-value for the reaction of phenyl acetaldehyde is similar to the one obtained for benzaldehyde. Had the oxidative addition been rate determining, then a lower slope in the Hammett plot would be expected as the homo-benzylic position at which the reaction occurs is not in conjugation with the Jt-system. 

The commercially available acetaldehyde (34) serves as a donor for aldol reactions, but undesirable side products are generally formed because of its very high degree of reactivity. In 2002, the (S)-proline catalyzed self-aldol reaction of this acetaldehyde was reported the reaction yielded over-reacting (-F)-(5S)-hydroxy-(2 )-hexenal with 57 to 90% ee [21]. The synthetically challenging i-hydroxy a-unsubstituted... 

Corbett, M. D. 1974. Hydroxamic acids from the reaction of active acetaldehyde with aromatic nitroso compounds. Bioorg. Chem. 3 361-365. 

When a mixture of aniline, hydrochloric acid and acetaldehyde is heated (in the absence of an oxidising agent), a vigorous reaction occurs with the pro duction of quinaldine. In these circumstances, the main reactions are undoubtedly, (i) the acetaldehyde undergoes the aldol condensation, and the... 

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