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Examples of this [contradictory] include the common undergraduate organic lab experiment involving the acetylation of salicylic acid to yield aspirin. Fischer esterification is primarily a thermodynamically-controlled process: because of its slowness, the most stable ester tends to be the major product. This can be a desirable trait if there ...
The ensuing reaction results in the cleavage of the ether or the ester into an alkyl iodide and respectively an alcohol or a carboxylic acid. Zeisel determination. By heating this mixture, the gases are allowed to come into contact with a piece of paper higher up the test tube saturated with silver nitrate.
An ester of carboxylic acid.R stands for any group (organic or inorganic) and R′ stands for organyl group.. In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (−R).
In organic chemistry, an ortho ester is a functional group containing three alkoxy groups attached to one carbon atom, i.e. with the general formula RC(OR') 3. Orthoesters may be considered as products of exhaustive alkylation of unstable orthocarboxylic acids and it is from these that the name 'ortho ester' is derived.
This reagent is common in the laboratory; its use cogenerates acetic acid. [7] [10] Acetyl chloride. This reagent is also common in the laboratory, but its use cogenerates hydrogen chloride, which can be undesirable. [8] Ketene. At one time acetic anhydride was prepared by the reaction of ketene with acetic acid: [11]
Acetyl chloride is a reagent for the preparation of esters and amides of acetic acid, used in the derivatization of alcohols and amines. One class of acetylation reactions are esterification, for example the reaction with ethanol to produce ethyl acetate and hydrogen chloride: CH 3 COCl + HO−CH 2 −CH 3 → CH 3 −COO−CH 2 −CH 3 + HCl
The reaction can also be accomplished with the help of enzymes, particularly lipases (one example is the lipase E.C.3.1.1.3 [2]). Transesterification : alcohol + ester → different alcohol + different ester
Alkaline hydrolysis of esters is also known as saponification. A base such as sodium hydroxide is required in stochiometric amounts. Unlike acid-catalyzed ester hydrolysis, it is not an equilibrium reaction and proceeds to completion. Hydroxide ion attacks the carbonyl carbon to give a tetrahedral intermediate, which then expels an alkoxide ion.