Carbonylation higher alcohols

In general aldehydes and ketones have higher boiling points than alkenes because they are more polar and the dipole-dipole attractive forces between molecules are stronger But they have lower boiling points than alcohols because unlike alcohols two carbonyl groups can t form hydrogen bonds to each other... 

A facile method for the oxidation of alcohols to carbonyl compounds has been reported by Varma et al. using montmorillonite K 10 clay-supported iron(III) nitrate (clayfen) under solvent-free conditions [100], This MW-expedited reaction presumably proceeds via the intermediacy of nitrosonium ions. Interestingly, no carboxylic acids are formed in the oxidation of primary alcohols. The simple solvent-free experimental procedure involves mixing of neat substrates with clayfen and a brief exposure of the reaction mixture to irradiation in a MW oven for 15-60 s. This rapid, ma-nipulatively simple, inexpensive and selective procedure avoids the use of excess solvents and toxic oxidants (Scheme 6.30) [100]. Solid state use of clayfen has afforded higher yields and the amounts used are half of that used by Laszlo et al. [17,19]. 

The essential factor which differentiates the monomeric and dimeric carbonylations seems to be the presence or absence of halide ion coordinated to the palladium. The dimerization-carbonylation proceeds satisfactorily with halide-free palladium phosphine complexes. Most conveniently, Pd(OAc)2 is used with PPh3. PdCl2(PPh3)2 can be used as a catalyst with addition of an excess of bases. The reaction is carried out at 1I0°C under 50 atm of carbon monoxide pressure in alcohol. Higher... 

In order to obtain a deep characterization and differentiation of Madeira wines according to main grape varieties (Camara et ah, 2006a,b,c), multivariate analysis was applied to varietal, prefermentative, and fermentative data on terpenoids, Ce alcohols, higher alcohols, fatty acids, ethyl esters, and carbonyl compounds. The results showed that Malvasia wines had the... 

Carbonylation of Higher Alcohols Higher Carboxylic Acids... 

Higher alcohols. Acids, Carbonyls Volatile sulfur compounds... 

Oxidation of alcohols. CrO, (l.B-2.0 equiv.) in a mixture of diethyl ether and dichloromethane (1 3) is useful for oxidation of alcohols to carbonyl compounds. Yicids are higher and work-up simpler if Celite is added. Aldehydes undergo further oxidation to carboxylic acids, but ketones and a -diketones are stable. The reagent is mil suitable for allylic oxidation. ... 

Oxidation of primary and secondary alcohols to carbonyl compounds. Corey and Kim2 report that the complex of N-chlorosuccinimide and dimethyl sulfide is somewhat superior to the complex of dimethyl sulfide and chlorine (this volume) for oxidation of primary and secondary alcohols the formation of hydrogen chloride is avoided and yields are generally higher. The procedure is illustrated for the oxidation of 4-/-butyl-cyclohexanol (2) to 4-r-butylcyclohexanone (4). The complex (1) is prepared by addition of dimethyl sulfide (4.1 mmole) to a stirred solution of NCS (3.0 mmole) in toluene at 0° under argon. The mixture is cooled to -25° and a solution of 4-r-butylcyclo-hexanol (2.0 mmole, mixture of cis and trans) in toluene is added dropwise. The stirring is continued for 2 hr. at — 25° and then triethylamine (3.0 mmole) in toluene is added dropwise. The ketone (4) is obtained in almost quantitative yield. As in oxidation with the complex of dimethyl sulfide and chlorine, an intermediate sulfoxonium complex (3) is involved. 

Higher Fatty Acids. Oxidation of higher paraffins can give mixtures of acids, alcohols, and carbonyl compounds, although fatty acids may be obtained as the principal product. Publications by Wittka (126), Stossel (111), Allen (3), Lanning (62), Zabel (128), and Gall (35) are of importance in this field. 

Oxysulfides and mercaptans of carbonyl compounds with the above mentioned mercaptans Methyl alcohol Higher aliphatic alcohols Acetol... 

Isomerization of allylic aicohois. This cationic complex (1) is a very active catalyst for hydrogenation of alkenes, even of tri- and tetrasubstituted alkenes. Since it can sometimes effect isomerization of the substrate as well, it was examined as a catalyst for isomerization of allylic alcohols to carbonyl compounds, a reaction that ordinarily requires fairly drastic conditions. After activation with hydrogen, 1 can effect this isomerization in THF at 20°. Primary and secondary allylic alcohols with monosubstituted double bonds are isomcrized in quantitative yield at 20°, Alcohols with more substituted double bonds require more catalyst and/or higher temperatures (60°). Dismutation is not observed in this system. Examples ... 

Oxidation of Alcohols. Diphenyl sulfoxide has been employed as an oxidant in conjunction with molybdenum (VI) and osmium (VIII) catalysts for the conversion of alcohols to carbonyl compounds. Diphenyl sulfoxide in combination with catalytic quantities of Mo02(acac)2 oxidizes alcohols to ketones or aldehydes. Higher yields are obtained with allylic or benzylic alcohols. Catal)dic OSO4 in association with Ph2SO can oxidize primary and secondary alcohols to aldehydes and ketones in the... 

Most types of wild and cultivated edible mushrooms of the phyla Basidiomycota (club fungi) and Ascomycota (sac fungi), which cover most of the so-caUed higher fungi, contain as the key compound alcohol (E)-oct-l-en-3-ol, which is produced by enzymatic oxidation of hnoleic acid. Oct-l-en-3-ol is accompanied by a number of other compounds. For example, the components of common mushroom Agaricus bisporus) aroma are the following alcohols and carbonyl compounds 3-methylbutan-1 -ol, (R) -octan-... 

Hydroformylation of olefins is one way to develop higher alcohols from CO. Actually, this reaction occurs through two steps. First step involves the formation of CO form CO2 and by RWGS reaction followed by hydroformylation of CO in the second step results in the formation of higher alcohols. Rhuthenium carbonyl complex and Ru-based clusters were reported to be highly active for this reaction [68-71]. 

The stoichiometric and the catalytic reactions occur simultaneously, but the catalytic reaction predominates. The process is started with stoichiometric amounts, but afterward, carbon monoxide, acetylene, and excess alcohol give most of the acrylate ester by the catalytic reaction. The nickel chloride is recovered and recycled to the nickel carbonyl synthesis step. The main by-product is ethyl propionate, which is difficult to separate from ethyl acrylate. However, by proper control of the feeds and reaction conditions, it is possible to keep the ethyl propionate content below 1%. Even so, this is significantly higher than the propionate content of the esters from the propylene oxidation route. 

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