Quiz - Alcohols, Ethers, and Epoxides - 2 | Alcohols, Ethers, and Epoxides - Synthesis

Organic Chemistry 1 - Quiz - Alcohols, Ethers, and Epoxides - 2

1

Which reagent is most suitable for converting an aldehyde into a primary alcohol?

NaBH4 is a mild reducing agent suitable for the reduction of aldehydes to primary alcohols. LiAlH4 is also a strong reducing agent that can perform this reaction, but NaBH4 is generally preferred for ketones. PCC is an oxidizing agent and Grignard reagents are used for different types of synthesis reactions.

2

What best describes the reaction mechanism when a primary alkyl halide reacts with NaOH to form an alcohol?

The reaction between a primary alkyl halide and NaOH to form an alcohol involves an SN2 mechanism, where the nucleophile (OH-) attacks the electrophilic carbon, displacing the halide ion in a single concerted step.

3

Which of the following reactions will form an epoxide in the presence of a peracid, such as mCPBA?

The reaction of an alkene with a peracid, such as mCPBA (meta-chloroperoxybenzoic acid), will yield an epoxide via an electrophilic addition. This process is known as the Prilezhaev reaction. The other options are not associated with epoxide formation under these conditions.

4

When synthesizing an alcohol from an aldehyde using an organometallic reagent like a Grignard reagent, which product results?

An aldehyde will react with a Grignard reagent to produce a secondary alcohol after protonation work-up. The Grignard reagent adds to the carbonyl carbon atom, forming an adduct that yields a secondary alcohol.

5

What is the best method to prepare a symmetrical ether from an alcohol?

Acid-catalyzed dehydration of alcohols can lead to the formation of symmetrical ethers when heated with an acid catalyst such as sulfuric acid. This is also known as intermolecular dehydration. Williamson Ether Synthesis is typically used for the synthesis of asymmetrical ethers.

6

Which reagent would you use to oxidize a primary alcohol to an aldehyde without further oxidation to a carboxylic acid?

Pyridinium chlorochromate (PCC) is often used to oxidize primary alcohols to aldehydes without further oxidation to carboxylic acids due to its milder conditions compared to other strong oxidizing agents like CrO3, KMnO4, or Na2Cr2O7.

7

Which starting material and reagent would be most appropriate for the synthesis of a tertiary alcohol via an SN1 mechanism?

A tertiary alkyl halide will react with water or an alcohol via an SN1 mechanism, forming a carbocation intermediate that readily captures a nucleophile, leading to a tertiary alcohol. Secondary and primary alkyl halides favour SN2 mechanisms, and NaBH4 is a reducing agent.

8

In the context of green chemistry, which solvent would be most appropriate for an SN2 reaction?

DMSO is a polar aprotic solvent that is frequently used in SN2 reactions due to its ability to stabilize the transition state and speed up the reaction. It is also considered a better choice in terms of green chemistry compared to halogenated solvents like DCM.