Propionaldehydes methyl ketones

The attack of OH- anion obeys the Markovnikov rule. The oxidation of propylene affords acetone. Propionaldehyde is not formed. Higher alkenes are oxidized to ketones. This means that the oxidation of terminal alkenes affords methyl ketones 8, which are useful synthetic intermediates. Based on this reaction, terminal alkenes can... 

Sodium methoxide Propionaldehydes from methyl ketones... 

Figure 5.6 Alcohols, aldehydes, ketones and acids 15, ethylene glycol 16, vinyl alcohol 17, acetaldehyde 18, formaldehyde 19, glyoxal 20, propionaldehyde 21, propionaldehyde 22, acetone 23, ketene 24, formic acid 25, acetic acid 26, methyl formate. (Reproduced from Guillemin et at. 2004 by permission of Elsevier)...

Butenes were subjected to photosensitized reaction with molecular oxygen in methanol. 1-Butene proved unreactive. A single hydroperoxide, l-butene-3-hydroperoxide, was produced from 2-butene and isolated by preparative gas chromatography, Thermal and catalyzed decomposition of pure hydroperoxide in benzene and other solvents did not result in formation of any acetaldehyde or propionaldehyde. The absence of these aldehydes suggests that they arise by an addition mechanism in the autoxidation of butenes where they are important products. l-Butene-3-hydroperoxide in the absence of catalyst is converted predominantly to methyl vinyl ketone and a smaller quantity of methyl vinyl carbinol —volatile products usually not detected in important quantities in the autoxidation of butene. 

Enantioselective aldol condensation. Masamtinc et al. have prepared optically pure /Miydroxy-a-methyl carboxylic acids by aldol condensation with the (S)- and (RHsomers of the ethyl ketone I, prepared in three steps from commercially available (S)- and (R>mandelic acid. For example, (SH is converted into the (Z)-boron cnolatc (2), which condenses with propionaldehyde to form a single aldol... 

Formaldehyde, acetaldehyde, acetone, and carbon monoxide were common combustion products of the four hexanes. Propionaldehyde, n-butyraldehyde, acrylic aldehyde, crotonic aldehyde, and methyl ethyl ketone were all found as intermediates in the combustion of n-hcxane. Acetaldehyde and acetone were prominent and propionaldehyde and acrylic aldehyde were present among the intermediates from 2-methylpentane. Acetaldehyde and methyl ethyl ketone were peculiarly characteristic of 3-methyl-pentane and acetaldehyde, acetone, and pivalic aldehyde were characteristic of 2,2-dimethylbutane. In other words, the intermediate monocarbonyl combustion products... 

DA, MEK, methyl vinyl ketone (MVK), propionaldehyde (PrH), and acetaldehyde (AcH) were analysed by on-line gas chromatography using a Varian 3400 GC equipped with a thermal conductivity detector and a 2m column containing 25% w/w B.B -oxydipropionitrile on Chromosorb W (80-100 mesh) operated at 60°C He was used as the carrier gas. Acetic acid (AcOH) was collected in 2ml of water from the effluent stream over a period of 1 hour and later analysed on a Porapak QS column at 150°C. CO2 was tested by removal of 2ml samples from the exit of the reactor with a gas syringe and injecting them onto a Porapak QS column operated at 60°C. 

Data for aliphatic aldehyde enolisation are very scarce, probably because the enolisation process is often complicated by oxidation and hydration. Nevertheless, the rate constants for base- and acid-catalysed iodination of R R2CHCHO were determined in aqueous chloroacetic acid-chloroacetate ion buffers (Talvik and Hiidmaa, 1968). The results in Table 4 show that alkyl groups R1 and R2 increase the acid-catalysed reactivity in agreement with hyperconjugative and/or inductive effects. This contrasts with aliphatic ketones for which steric interactions are important and even sometimes dominant. Data for base-catalysis are more difficult to interpret since a second a methyl group, from propionaldehyde to isobutyraldehyde, increases the chloroacetate-catalysed rate constant. This might result from a decrease of the a(C—H) bond-promoted hyperconjugative stabilisation of the carbonyl compound... 

An example of this method is given by the synthesis of brevicomin. The desired a-(phenylthio) ether (7) was made by Diels-Alder addition of phenyl vinyl sulfide and methyl vinyl ketone. Treatment of (7) with lithium l-(dimethylamino)naphthalenide, followed by trapping of the anion with propionaldehyde and ring closure to an acetal during the acidic work-up, afforded a mixture of endo and exo isomers of brevicomin (Scheme 36). 

CO, CH4, CO2, acetone, ketene. ethene. propene. 1-butene, benzene, toluene, xylene, cydopentene, methyl ethyl ketone, diethyl ketone, methyl-n-propyl ketone, di-n-propyl ketone, methyl vinyl ketone, methyl Isopropenyl ketone, methyl isopropyl ketone, ethyl vinyl ketone, trace amounts of methyl-n-bulyl ketone, cyclopentanone, cydohexanone. acrolein, ethanal. butanal. chain fragments, some monomer CO. CH4, COj, ketene, 1-butene, propene, acetone, methyl ethyl ketone, methyl n-propyl ketone, 1,4-cyclohexadiene. toluene, l-methy. l.3-cydohexadlene, 2-hexanone, cydopentene, 1-methyl cydopentene. mesityl oxide, xylenes, benzene, ethene, cyclopentanone, 1.3-cyclopentad iene, diethyl ketone, short chain fragments, traces of monomer CO, CH4, COi, ketene, 1-butene, propene, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl-n-propyl ketone, diethyl ketone, methyl propenyl ketone, 3-hexanone. toluene, 2-hexanone. 1,3-cydopentadiene, cyclopentanone, 2-melhylcydopenlanone, mesityl oxide, xylenes, benzene, propionaldehyde, acrolein, acetaldehyde ethene, short chain fragments, traces of monomer CO, COj, H2O, CH4. acetone, ketene, ethene, propylene, 1-butene, methyl vinyl ketone, benzene, acrylic add, toluene, xylene, short chain fragments such as dimer to octamer with unsaturated and anhydride functionalities... 

Adkins and Krsek noted that certain a,/3-unsaturated carbonyl compounds undergo reduction rather than hydroforraylation. Thus crotonaldehyde and acrolein are reduced to n-butyraldehyde and propionaldehyde, respectively, and methyl vinyl ketone is reduced to methyl ethyl ketone. Orchin and co-workers found that if the reaction is carried out at a higher temperature (180-185°) the carbonyl group is reduced as well. Indeed application of the 0x0 reaction to an alcohol leads to homologation ... 

In epoxidation, the propene-to-CHP molar ratio is 10 1, the reaction temperature is 60 °C and the pressure is sufficient to maintain propene in the liquid phase. The feed to the epoxidation reactor must contain less than 1% water in order to limit the hydrolysis of PO to glycol. The reaction is catalyzed by a proprietary, silylated, titanium-containing silicon oxide catalyst. The conversion of CHP is greater than 95%. Selectivity for PO based on hydroperoxide is 95%, whereas selectivity based on propene is around 99%. By-products of the reaction are aldehydes, such as acetaldehyde and propionaldehyde, alcohols (methanol and propene glycol), ketones and esters (e.g., acetone and methyl formate). The catalyst fixed-bed is structured into multiple catalyst layers, with heat exchangers in between the layers. This prevents excessive increases in temperature due to the exothermal reaction that would cause both thermal decomposition of the hydroperoxide and consecutive reactions of PO. 

Formaldehyde. Oxidation with air or oxygen of natural gas or propane and butane yields not only formaldehyde but also acetaldehyde, propionaldehyde, acetone, methyl ethyl ketone, tetrahydrofuran, methanol, propanol, butyl alcohols, and formic, acetic, and propionic acids. Such literature is covered by Walker (120, 121). Two reports on German processes for oxidation of methane to formaldehyde are given by Sherwood (254), and by Holm and Reichl (47). One of these processes indicates the almost exclusive formation of formaldehyde it is also indicated that the process was applied to ethane and propane with similar results. 

An odor is not only impacted by the concentration of individual compounds, but also by die relative balmice (ratio) among volatile compounds, and by semi- and non-volatile compounds. It is likely that other non-sulfur compounds are also involved in die development of irradiation odor. The possible non-sulfiir volatile confributors to the irradiation odor may include acetaldehyde, acetone, ethanol, methanol, methyl ediyl ketone, nonanal and phenylacetaldehyde (P). A mixture of 3-(metiiylthio)propionaldehyde (methional), nonanal and phenylacetaldehyde has been shown to have a similar odor as irradiation odor in beef (22,29). 

P, N] The addition of the enamines derived from a-phenyl-propionaldehyde and chiral amines to methyl vinyl ketone was the subject of an early investigation by Yamada and co-workers (Scheme 12, Table 2). Three types of chiral amine were used. The first set (entries 1-17) were derived from proline (25, 26). Additionally, some diamines derived from proline (entries 18-23) (27) and alkylamine mimics of proline were later examined (entries 24-27) (28). 

Chloramine-T, the sodium salt of A-chloro-p-tolucncsulfonamidc, tosylami-nates a number of in situ generated enamines of a-substituted propionaldehydes (see Eq. 78), a-substituted arylacetaldehydes, and methyl arylmethyl ketones.78... 

The cyclic tetraazadienes were first discovered by Curtis (Curtis, 1960 Curtis and House, 1961). These macrocycles were prepared by reacting 1,2-diaminoethane, 1,2-diaminopropane, or 1,3-diaminopropane with acetone, methyl ethyl ketone, propionaldehyde, n-butyraldehyde, isobutyraldehyde, or other small carbonyl compounds in the presence of Ni(II) or Cu(II) (Blight and Curtis, 1962 House and Curtis. 1962, 1964a, 1964b). Similar tetraaza macrocycles can be isolated from the reaction of triethylenetetraamine and the carbonyl compound in the presence of the metal template ions (Curtis... 

Cyclocondensations of simple carbonyl compounds—such as acetone, methyl ethyl ketone, propionaldehyde, or the butyraldehydes—and simple diamines—such as ethylenediamine and 1,2- or 1,3-propanediamine—were studied by Curtis and coworkers in the 1960s (Curtis, 1968). The resulting complexed cyclic bis Schiff base was reduced to form the tetraaza-crown ligand. The cyclic product is a result of an aldol condensation of the carbonyl compound, followed by ring-closure reactions with the diamine. In 1966,... 

Propionaldehyde 15. Methyl-i-butyl ketone/Methyl-i ec-butyl ketone... 

A. Saturated compounds Aliphatic aldehydes and ketones such as acetaldehyde, propionaldehyde, aldol, acetone, methyl ethyl ketone, ethyl-acetoacetate, and acetonylacetone are hydrogenated by ruthenium at atmospheric conditions as illustrated in Table I, No. 1-10. 

Show how the molecular weights of acetone, propionaldehyde, and methyl ethyl ketone can be estimated from the mass spectra in the figure below. Suggest a possible origin for the strong peaks of mass 57 in the spectra of methyl ethyl ketone and propionaldehyde, which is in accord with the fact that this peak is essentially absent in acetone, although acetone shows a strong peak at 43. 

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