Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Barium primary alcohols

Tishchenko (79), using a modified form of Raney nickel, obtained a 95.7 % yield of camphor from the dehydrogenation of borneol. Rutovskii, (80) received a 93.5% yield of camphor with Raney alloy. Reeves and Adkins (81), studying the dehydrogenation of primary alcohols, removed the hydrogen with ethylene. It was found that, though Raney nickel could be used for a catalyst for the reaction, the yields were low and, in general, the Raney nickel was inferior to a catalyst composed of copper, zinc, nickel, and barium chromite. [Pg.434]

Another commercial aldehyde synthesis is the catalytic dehydrogenation of primary alcohols at high temperature in the presence of a copper or a copper-chromite catalyst. Although there are several other synthetic processes employed, these tend to be smaller scale reactions. For example, acyl halides can be reduced to the aldehyde (Rosemnund reaction) using a palladium-on-barium sulfate catalyst. Formylation of aryl compounds, similar to hydrofomiylation, using HCN and HQ (Gatterman reaction) or carbon monoxide and HQ (Gatterman-Koch reaction) can be used to produce aromatic aldehydes. [Pg.472]

Phillips, J. W. C. and Mumford, A. (1934). Dimorphism of certain aliphatic compounds. V. Primary alcohols and their acetates. J. Chem. Soc., 1657-65. [98] Pierce-Butler, M. A. (1982). Structures of the barium salt of 2,4,6-trinitro-l,3-benzenediol monohydrate and the isomorphous lead salt (/3-polymorph). Acta Crystallogr B, 38, 3100. [294]... [Pg.376]

A copper-chromium oxide on pumice catalyst has particular value for the dehydrogenation of primary and secondary alcohols to the corresponding carbonyl compounds (see Section 5.6.1, p. 581). Dissolve 10.4g of barium nitrate (AnalaR) in 280 ml of water at about 80 °C and add to this hot solution 87 g of copper(n) nitrate trihydrate (AnalaR) stir the mixture and heat until a homogeneous solution results. Prepare a solution of 50.4 g of recrystallised ammonium dichromate in a mixture of 200 ml of water and 75 ml of concentrated ammonia solution (d 0.880). To the ammonium chromate solution at 25-30 °C add the hot (80 °C) nitrate solution in a thin stream with stirring. Allow the mixture to cool and filter off the yellowish-brown precipitate with suction press with a glass stopper and suck as dry as possbile. Transfer the... [Pg.427]

The oxidation of diols having alcoholic groups of the same nature, for example, both alcoholic groups are primary, secondary, allylic, or benzylic, is usually carried out at both groups to yield dialdehydes [832] or diketones [552], Such reactions are achieved by chromium trioxide [582], barium manganate [832], dimethyl sulfoxide activated with acetic anhydride [1013], and others (equations 284 and 285). [Pg.155]

It is very interesting that by using alkaline-earth catalysts in the ethoxylation reaction (Ca, Sr or Ba alcoholates or carboxylates), a narrower distribution of EO sequences per hydroxyl group resulted, compared to use of alkaline catalysts. For example, with barium alcoholate as catalyst around 80-85% primary hydroxyl, at 15% EO as terminal block, are obtained with polyether triols (MW of 5000 daltons), compared to 65-75% primary hydroxyl obtained in the presence of KOH. The explanation of this behaviour... [Pg.111]

By Oxidation of Alcohols.—Barium manganate is readily available and stable, and has been recommended for the oxidation of primary and secondary alcohols to aldehydes and ketones respectively. Chromic acid adsorbed on to silica geP and the recyclable poly[vinyl(pyridinium chromate)] effect the same changes, while acid-stable primary and secondary alcohols are oxidized rapidly using potassium dichromate, sulphuric acid, methylene chloride, and a phase-transfer catalyst." Benzeneseleninic anhydride is an alternative reagent for the oxidation of alcohols under essentially neutral conditions. ... [Pg.36]

The readily available and stable compound barium manganate has been shown to be an efficient oxidizing agent for the oxidation of primary and secondary alcohols to carbonyl compounds. It has similar activity to manganese dioxide but is claimed to be better for the preparation of certain aldehydes e.g. the furan aldehyde (11) is produced in 80% yield whereas with Mn02 the yield is less than 20%. [Pg.187]

A second procedure devised for the controlled shift of the conformational equilibrium in AMAA derivatives consists of the addition of a metal salt that is capable of stabilizing a certain conformer by complexation. Approaches for secondary alcohols" and primary amines are described in the literature. In both cases, MPA was used as the auxiliary reagent and barium(II) as the chelating agent. [Pg.91]


See other pages where Barium primary alcohols is mentioned: [Pg.472]    [Pg.247]    [Pg.177]    [Pg.247]    [Pg.89]    [Pg.71]    [Pg.100]    [Pg.89]    [Pg.346]    [Pg.307]    [Pg.236]    [Pg.144]    [Pg.272]    [Pg.273]    [Pg.341]    [Pg.24]    [Pg.307]    [Pg.58]    [Pg.189]    [Pg.509]    [Pg.277]    [Pg.790]    [Pg.707]    [Pg.935]    [Pg.976]    [Pg.165]    [Pg.336]    [Pg.174]    [Pg.937]    [Pg.401]    [Pg.237]    [Pg.210]    [Pg.372]    [Pg.392]    [Pg.3]    [Pg.85]   
See also in sourсe #XX -- [ Pg.7 , Pg.307 ]




SEARCH



Alcohols, primary

Barium alcoholate

© 2024 chempedia.info