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The Chugaev elimination is the pyrolysis of a xanthate ester, resulting in an olefin. [1] [13] To form the xanthate ester, an alcohol reacts with carbon disulfide in the presence of a base, resulting in a metal xanthate which is trapped with an alkylating agent (typically methyl iodide).
Methylecgonidine (anhydromethylecgonine; anhydroecgonine methyl ester; AEME) is a chemical intermediate derived from ecgonine or cocaine.. Methylecgonidine is a pyrolysis product formed when crack cocaine is smoked, making this substance a useful biomarker to specifically test for use of crack cocaine, as opposed to powder cocaine which does not form methylecgonidine as a metabolite. [1]
The Chugaev elimination is similar in mechanism to other thermal elimination reactions such as the Cope elimination and ester pyrolysis. Xanthates typically undergo elimination from 120 to 200 °C, while esters typically require 400 to 500 °C and amine oxides routinely react between 80 and 160 °C.
Methyl esters are often susceptible to decarboxylation in the Krapcho decarboxylation. Phenyl esters react to hydroxyarylketones in the Fries rearrangement. Specific esters are functionalized with an α-hydroxyl group in the Chan rearrangement. Esters with β-hydrogen atoms can be converted to alkenes in ester pyrolysis.
Ester pyrolysis in organic chemistry is a vacuum pyrolysis reaction converting esters containing a β-hydrogen atom into the corresponding carboxylic acid and the alkene.The reaction is an E i elimination and operates in a syn fashion.
The cleavage of the aliphatic chain occurs in this variant of the steam cracking selectively between the hydroxymethylene and the allyl-methylene group. Besides heptanal and methyl undecenoate, a mixture of methyl esters of saturated and unsaturated C18-carboxylic acids is obtained. This mixture is known under the trade name Esterol and is used ...
There is no antiperiplanar requirement. An example is the pyrolysis of a certain sulfonate ester of menthol: E1 elimination Nash 2008, antiperiplanar relationship in blue Only reaction product A results from antiperiplanar elimination. The presence of product B is an indication that an E1 mechanism is occurring. [3]
Undecylenic acid is prepared by pyrolysis of ricinoleic acid, which is derived from castor oil. Specifically, the methyl ester of ricinoleic acid is cracked to yield both undecylenic acid and heptanal. The process is conducted at 500–600 °C in the presence of steam. [1] [2] The methyl ester is then hydrolyzed. Pyrolyse von ...