36 Questions
What is the product formed from the bromination of furan in the presence of alcohol?
2,5-dialkoxy-2, 5-dihydrofurans
Why can furan behave as a diene in Diels-Alder reactions?
Due to the high electronegativity of the oxygen atom
What is the catalyst used in the industrial synthesis of pyrrole from furans?
Alumina
What type of reaction involves replacement of hydrogen or carbon dioxide from an acid in the mercuration of furan?
Substitution reaction
What does the formylation of furan involve?
Gattermann Koch formylation
What is Raney Ni composed mostly of?
Nickel
What is the strongest base required for the synthesis of furan from carbohydrates?
NaOH
In the synthesis of furan from carbohydrates, what is the first step?
Distillation of CH with sulfuric acid
Which statement about the properties of furan is correct?
Furan has a boiling point of 31.4°C and is highly volatile at room temperature
In electrophilic substitution reactions of furan, which position is primarily substituted?
The 2-position
What is the reason given for furan undergoing electrophilic substitution at the 2-position?
Attack at the 2-position gives more resonance contributing structures
What is the yield of furan reported by Wilson when furoic acid is heated to 200°C without a catalyst?
78%
What is the key factor that contributes to the aromaticity of furan?
The presence of a planar ring structure with parallel p orbitals allowing for delocalization of electrons
Which of the following is NOT a method for the industrial synthesis of furan?
Acid-catalyzed dehydration of sucrose
In the Paal-Knorr synthesis of furan, what type of reaction occurs?
Cyclizing dehydration
What is the role of the base in the Feist-Benary synthesis of furan?
To remove a proton from the α-haloketone, generating an enolate
Which of the following statements about furan is correct?
Furan can act as a diene in Diels-Alder reactions due to the delocalization of electrons in the ring
What is the primary medicinal use of furan derivatives?
Anticancer drugs
Which of the following statements about the aromaticity of furan is correct?
Furan is aromatic because it has 6 delocalized pi electrons following Hückel's rule.
In the Paal-Knorr synthesis of furan, what type of reaction occurs?
Acid-catalyzed cyclizing dehydration reaction
Which of the following is the correct mechanism for the Feist-Benary synthesis of furan?
A base-catalyzed condensation reaction between an α-haloketone and a β-ketoester.
Which of the following reactions is NOT a method for the industrial synthesis of furan?
Acid-catalyzed dehydration of carbohydrates
In electrophilic substitution reactions of furan, which position is primarily substituted?
The 2-position
Which of the following statements about the properties of furan is correct?
Furan is a diene and can participate in Diels-Alder reactions.
What is the primary reason for the preference of electrophilic substitution at the 2-position over the 3-position in furan?
Substitution at the 2-position leads to a more stable resonance-stabilized intermediate.
What is the primary reason for furan's solubility in most organic solvents but insolubility in ether?
The aromatic nature of furan disrupts its ability to form dipole-dipole interactions with ether.
In the synthesis of furan from carbohydrates, what is the role of the sulfuric acid in the first step?
It acts as a dehydrating agent to remove water from the carbohydrate.
Which of the following statements about the properties of furan is incorrect?
Furan is soluble in water and most organic solvents.
In the reaction reported by Wilson, where a 78% yield of furan was obtained from furoic acid at 200°C without a catalyst, what was the likely mechanism?
Decarboxylation
Which of the following statements best explains why furan undergoes electrophilic substitution reactions primarily at the 2-position?
Substitution at the 2-position leads to a more stable resonance-stabilized intermediate.
What is the key factor that enables furan to undergo Diels-Alder cycloaddition reactions?
The high electronegativity of the oxygen atom reduces the aromaticity of furan.
In the bromination of furan in the presence of alcohol, what is the mechanism for the formation of 2,5-dialkoxy-2,5-dihydrofurans?
The alcohol acts as a nucleophile, adding to the C-5 position of the intermediate, followed by alcoholysis of the C-2 bromide.
Which of the following is the primary reason for using Raney Ni as a reducing agent in the reduction of furan derivatives?
Raney Ni is a fine-grained solid composed mostly of nickel, which provides a large surface area for the reduction to occur efficiently.
In the industrial synthesis of pyrrole from furans, what is the primary role of the alumina catalyst?
To promote the cycloaddition of furan with ammonia, forming the pyrrole ring.
Which of the following statements best describes the Gattermann-Koch formylation of furan?
It is a Vilsmeier-Haack type reaction that utilizes a formylating agent derived from an amine and a carbonyl compound.
Which of the following reactions is NOT a common method for the synthesis of furan derivatives?
Suzuki cross-coupling reactions involving furan-based boronic acids or esters.
Explore the properties, aromaticity, synthesis, reactions, and medicinal uses of the heterocyclic compound Furan in organic chemistry. Learn about the sp2 hybridization and planar structure of Furan rings.
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