Quiz - Alpha Carbon Chemistry - 2 | Enols and Enolates - Alpha Carbon Chemistry
Organic Chemistry 3 - Quiz - Alpha Carbon Chemistry - 2
Which statement best describes the acidity of the α hydrogen in carbonyl compounds?
The α hydrogen of a carbonyl compound is more acidic than a typical C-H bond due to the resonance stabilization of the resulting enolate ion. The electron-withdrawing effect of the carbonyl group helps stabilize the negative charge on the oxygen atom in the enolate, making the α hydrogen relatively acidic.
What is the significance of the alpha position in organic chemistry?
In organic chemistry, the alpha position refers to the carbon atom directly adjacent to a carbonyl group (C=O) in a molecule. This position is significant in reactions involving enolate intermediates, as it determines the site of nucleophilic attack or electrophilic substitution.
What is the primary purpose of the Hell-Volhard-Zelinski reaction in organic chemistry?
The Hell-Volhard-Zelinski reaction is used to introduce a halogen atom, typically bromine, onto the alpha position of a carboxylic acid.
What is the role of hydroxide ion in the haloform reaction mechanism?
The hydroxide ion attacks the carbonyl group of the methyl ketone, initiating the formation of a tetrahedral intermediate.
What role does the base play in alkylation via enolate ions?
The base used in alkylation via enolate ions deprotonates the carbonyl compound to generate the corresponding enolate ion, which then undergoes alkylation.
Which type of alkylating agent is commonly used in alkylation via enolate ions?
Alkyl halides are commonly used as alkylating agents in alkylation via enolate ions, where they react with the enolate ion to introduce the desired alkyl group onto the carbonyl compound.
What is the primary purpose of using a sterically hindered base in the alkylation of unsymmetrical ketones?
Sterically hindered bases like LDA are used to readily deprotonate the less hindered α position, favoring the formation of the kinetic enolate in the alkylation of unsymmetrical ketones.
Why is the alkylation of unsymmetrical ketones performed at low temperature (-78°C) when using a sterically hindered base?
Low temperature (-78°C) is used to prevent equilibration of the enolates formed, favoring the kinetic enolate in the alkylation of unsymmetrical ketones.
What type of reaction mechanism is involved in 1,3-dicarboxylic acid decarboxylation?
1,3-dicarboxylic acid decarboxylation involves a pericyclic reaction mechanism to form an enol intermediate.
What is the role of acid-catalyzed hydrolysis in the malonic ester synthesis?
Acid-catalyzed hydrolysis of the esters formed in the malonic ester synthesis leads to the formation of a 1,3-dicarboxylic acid intermediate.