(a)
Interpretation: Mechanism for the given type of decarboxylation reaction has to be proposed and it should be compared with the mechanism of decarboxylation of
Concept introduction:
Carboxylic acids contain a carbonyl attached to a hydroxyl group as shown below,
If
Decarboxylation of
The mechanism of thermal decarboxylation involves two processes,
- (i) Redistribution of electrons in a cyclic transition state.
- (ii) Cyclic transition state possesses keto-enol tautomerism.
(b)
Interpretation: Mechanism for the given type of decarboxylation reaction has to be proposed and it should be compared with the mechanism of decarboxylation of
Concept introduction:
Carboxylic acids contain a carbonyl attached to a hydroxyl group as shown below,
If carboxylic acid is heated to a very high temperature then of carbon dioxide will be eliminated from it this reaction is known as decarboxylation. Simple carboxylic acids do not decarboxylate readily.
Decarboxylation of
Simply the mechanism of thermal decarboxylation involves two processes,
- (i) Redistribution of electrons in a cyclic transition state.
- (ii) Cyclic transition state possesses keto-enol tautomerism.
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Chapter 17 Solutions
Organic Chemistry, Loose-leaf Version
- -Hydroxyketones and -hydroxyaldehydes are also oxidized by treatment with periodic acid. It is not the -hydroxyketone or aldehyde, however, that undergoes reaction with periodic acid, but the hydrate formed by addition of water to the carbonyl group of the -hydroxyketone or aldehyde. Write a mechanism for the oxidation of this -hydroxyaldehyde by HIO4.arrow_forwardFischer esterification cannot be used to prepare tert-butyl esters. Instead, carboxylic acids are treated with 2-methyIpropene in the presence of an acid catalyst to generate them. REFER IMAGE (a) Why does the Fischer esterification fail for the synthesis of tert-butyl esters?(b) Propose a mechanism for the 2-methylpropene method.arrow_forwardDraw the organic product(s) of the reaction of phenylacetaldehyde with KMnO4. H3O+arrow_forward
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- 4) Show the mechanism for the acid catalyzed hydrolysis of the ketal shown below. کارام H+, H₂O HO OHarrow_forwardN Ph :0: CH3 Primary amines add to aldehydes and ketones to give imines. Imines are formed in a reversible, acid-catalyzed process that begins with nucleophilic addition of the primary amine to the carbonyl group, followed by transfer of the proton to yield a neutral carbinolamine. Protonation of the hydroxyl group converts it into a good leaving group and an E1-like loss of water yields an iminium ion. Deprotonation yields the product imine and regenerates the acid catalyst. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing Instructions CH3 NH₂OH NH₂OH Ph- :0: OH CH3 CH3 36arrow_forward3 Treatment of 1-aminoadamantane, C„H„N, with methyl 2,4-dibromobutanoate in the presence of a nonnucleophilic base, R,N, involves two successive S,2 reactions and gives compound A. Propose a structural formula for compound A. R&N NH, + Br. C15H93NO, + 2 R,NH Br OCH Br 1-Aminoadamantane Methyl 2,4-dibromobutanoate Aarrow_forward
- The product in this reaction is basic enough to be protonated by a dilute HCl solution. Draw the protonated species, clearly showing where protonation occurs. Draw all possible resonance structures of the conjugate acid of the product, and use these to explain why the product is so much more basic than a typical ester, like ethyl acetate.arrow_forwardH₂C OEt H₂C OEt 1. NaOEt, EtOH 2. H₂O* H₂C EtOH OEt Esters, like aldehydes and ketones, are weakly acidic. Treatment of an ester with 1 equivalent of a strong base, such as sodium ethoxide, causes a reversible carbonyl condensation to occur that forms a ẞ-ketoester. This reaction is known as the Claisen condensation. The tetrahedral intermediate thus formed expels an alkoxide leaving group to give an acyl substitution product, a ẞ-ketoester. The steps leading up to this point are all reversible. The best yields for the Claisen condensation are obtained when the starting ester has more than one acidic a-hydrogen. In these cases, a second deprotonation of the a-carbon drives the reaction equilibrium toward the product, thus requiring a full equivalent of base instead of a catalytic amount. Subsequent protonation with dilute aqueous acid resultsn a high yield of the final product. Draw curved arrows to show the movement of electrons in this step of the mechanism. Arrow-pushing…arrow_forwardPhenyl 4-aminosalicylate is a drug used in the treatment of tuberculosis. Propose a synthetic route for this compound starting from 4-nitrosalicylic acid. The synthesis involves multiple steps. Specify all the reagents and the reaction conditions it may require in each step.arrow_forward
- Organic ChemistryChemistryISBN:9781305580350Author:William H. Brown, Brent L. Iverson, Eric Anslyn, Christopher S. FootePublisher:Cengage LearningEBK A SMALL SCALE APPROACH TO ORGANIC LChemistryISBN:9781305446021Author:LampmanPublisher:CENGAGE LEARNING - CONSIGNMENT