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With water and a protic acid such as sulfuric acid as the reaction medium and formaldehyde the reaction product is a 1,3-diol (3). When water is absent, the cationic intermediate loses a proton to give an allylic alcohol (4). With an excess of formaldehyde and a low reaction temperature the reaction product is a dioxane (5).
Illustrative is the conversion of isobutylene to tert-butylamine using HCN and sulfuric acid followed by base neutralization. The weight of the salt byproduct is greater than the weight of the amine. [12] In the laboratory, the Ritter reaction suffers from the necessity of an extremely strong acid catalyst.
The Woodward reaction mechanism. To eliminate the need for silver salts, Sudalai and coworkers modified the Prévost-Woodward reaction; the reaction is catalyzed with LiBr, and uses NaIO 4 and PhI(OAc) 2 as oxidants. [23] LiBr reacts with NaIO 4 and acetic acid to produce lithium acetate, which can then proceed through the reaction as ...
The general mechanism for primary alkyl halides is shown below. [8] Mechanism of Friedel–Crafts alkylation. For primary (and possibly secondary) alkyl halides, a carbocation-like complex with the Lewis acid, [R (+)---(X---MX n) (–)] is more likely to be involved, rather than a free carbocation.
Alkenes can be made from alcohols by dehydration. This conversion, among others, is used in converting biomass to liquid fuels. [2] The conversion of ethanol to ethylene is a fundamental example: [3] [4] CH 3 CH 2 OH → H 2 C=CH 2 + H 2 O. The reaction is accelerated by acid catalysts such as sulfuric acid and certain zeolites.
Two approaches are taken. Traditionally the alkene is treated with sulfuric acid to give alkyl sulphate esters. In the case of ethanol production, this step can be written: H 2 SO 4 + C 2 H 4 → C 2 H 5-O-SO 3 H. Subsequently, this sulphate ester is hydrolyzed to regenerate sulphuric acid and release ethanol: C 2 H 5-O-SO 3 H + H 2 O → H 2 ...
The mechanisms of these processes involve the addition of a tin-centered radical to the substrate followed by elimination of a sulfinyl radical, which abstracts a hydrogen from a molecule of tin hydride to propagate the radical chain. Protonation of the organotin intermediates thus formed (by sulfinic acid generated in situ) leads to reduced ...
The oxidation of primary alcohols to carboxylic acids can be carried out using a variety of reagents, but O 2 /air and nitric acid dominate as the oxidants on a commercial scale. Large scale oxidations of this type are used for the conversion of cyclohexanol alone or as a mixture with cyclohexanone to adipic acid. Similarly cyclododecanol is ...