Тест: Fundamental Organic Reactions and Syntheses — 9 въпроса

1. What is an acetylation name reaction?

A. A process where aldehydes are reduced to alcohols using hydrazine.

B. A reaction where an acetyl group is introduced into a molecule, typically using acetyl chloride or acetic anhydride.

C. A reaction that converts phenols into nitroso derivatives using nitrous acid.

D. A reaction that involves coupling two aromatic rings using a metal catalyst.

Answer: (B)

Обяснение

An acetylation name reaction is a chemical process in which an acetyl group (CH₃CO−) is introduced into an organic molecule, usually to modify or protect functional groups like hydroxyl or amino groups, often using reagents such as acetyl chloride or acetic anhydride.

2. Who were the chemists responsible for developing the Wurtz Fittig Reaction, and in which years did they publish their key findings?

A. Karl Wurtz in 1852 and R. Fittig in 1859

B. August Werner in 1870 and Emil Fischer in 1885

C. Hans Meerwein in 1920 and Robert Robinson in 1935

D. Henry Wurtz in 1860 and Friedrich Fittig in 1867

Answer: (A)

Обяснение

The Wurtz Fittig Reaction was developed by Karl Wurtz in 1852 and R. Fittig in 1859, combining their names and timelines to recognize their contributions in the 19th century.

3. Which of the following reagents and conditions are used in the Wurtz Fittig Reaction to couple aryl halides with alkyl halides?

A. Potassium permanganate in aqueous solution

B. Sodium or potassium metal in dry ether

C. Palladium on carbon with hydrogen

D. Hydrogen gas with a platinum catalyst

Answer: (B)

Обяснение

The Wurtz Fittig Reaction involves coupling aryl halides with alkyl halides using sodium or potassium metal in dry ether, facilitating the formation of biaryl or aryl-alkyl compounds. The other options describe different reactions: hydrogenation, catalytic reduction, and oxidation, which are not characteristic of the Wurtz Fittig Reaction.

4. What is the primary chemical process involved in the Wurtz Fittig reaction?

A. Coupling of aromatic compounds via electrophilic substitution

B. Coupling of two alkyl halides to form an alkane or aryl-alkyl compounds

C. Addition of halogens to alkenes

D. Oxidation of alcohols to ketones

Answer: (B)

Обяснение

The Wurtz Fittig reaction involves the coupling of two alkyl halides (or aryl halides) in the presence of sodium metal to form a new carbon-carbon bond, producing alkanes or substituted aromatics.

5. What is the primary role or purpose of the Wurtz Reaction in organic synthesis?

A. To synthesize esters from acids and alcohols

B. To remove oxygen from organic compounds

C. To couple alkyl halides into larger alkanes

D. To convert aldehydes into carboxylic acids

Answer: (C)

Обяснение

The Wurtz Reaction is primarily used to couple alkyl halides in the presence of sodium metal to form larger alkanes, thus creating new carbon-carbon bonds.

6. Which of the following best describes a typical reagent or condition used in the Wurtz Fittig Reaction?

A. Sodium metal in dry ether as a solvent

B. Diatomic oxygen at high temperature

C. Pyridine as a base in aqueous solution

D. Hydrogen gas over a platinum catalyst

Answer: (A)

Обяснение

Sodium metal in dry ether is a key reagent in the Wurtz Fittig reaction, facilitating the coupling of alkyl/aryl halides through a metal-mediated process.

7. What is a common limitation or challenge associated with the Wurtz Fittig Reaction?

A. Tendency to produce symmetrical products only

B. Require high temperatures that cause decomposition

C. Limited to the formation of aromatic compounds only

D. Inability to use with alkyl halides that contain functional groups

Answer: (A)

Обяснение

The Wurtz Fittig reaction often produces symmetrical products, especially when identical halides are used, which limits its selectivity for asymmetric coupling.

8. How does the Wurtz Fittig reaction differ from the simpler Wurtz reaction?

A. It involves the coupling of aromatic halides and was developed later, incorporating Fittig’s contributions

B. It replaces sodium with potassium as the reducing agent

C. It involves oxidation instead of reduction

D. It is used specifically for the synthesis of esters

Answer: (A)

Обяснение

The Wurtz Fittig reaction is a variation that typically involves aryl halides and is associated with Fittig’s modifications, distinguishing it from the original Wurtz reaction, which mainly couples alkyl halides.

9. In which type of organic synthesis or research is the Wurtz Fittig reaction primarily utilized?

A. Synthesis of complex polymers and hydrocarbons

B. Preparation of biaryl compounds and other aromatic hydrocarbons

C. Oxidation of alcohols to aldehydes

D. Formation of esters from acyl chlorides and alcohols

Answer: (B)

Обяснение

The Wurtz Fittig reaction is mainly used in aromatic chemistry to synthesize biaryl compounds and related aromatic hydrocarbons through coupling of halogenated aromatic precursors.