Question 1

Which of the following statements best explains why ethers are commonly used as solvents in organic reactions?

Accepted Answer

Ethers are unreactive under most conditions, making them ideal solvents.

Question 2

What is the IUPAC name for the following compound: $$\mathrm{CH_3OCH_2CH_3}$$?

Accepted Answer

Methoxyethane

Question 3

Which IR absorption range is characteristic for the C–O stretch in ethers?

Accepted Answer

$$1000-1200\ \mathrm{cm}^{-1}$$

Question 4

In the Williamson ether synthesis, which combination of reactants would be most successful?

Accepted Answer

A primary alkyl halide and a strong alkoxide

Question 5

Which of the following best describes the mechanism for the acid-catalyzed cleavage of ethers with HI?

Accepted Answer

The ether oxygen is protonated, followed by nucleophilic attack by iodide ion.

Question 6

Why can't phenol be converted to a phenyl halide via SN2 cleavage of a phenyl ether?

Accepted Answer

SN2 reactions cannot occur on sp2-hybridized carbons.

Question 7

Which of the following is a major safety concern when storing ethers?

Accepted Answer

Ethers can form explosive peroxides upon exposure to air.

Question 8

What is the product of the reaction between ethylthiolate ($$\mathrm{CH_3CH_2S^-}) $$and 1-bromopropane ($$\mathrm{CH_3CH_2CH_2Br}$$)?

Accepted Answer

Ethyl propyl sulfide ($$\mathrm{CH_3CH_2S-CH_2CH_2CH_3})$$

Question 9

Which reagent is commonly used to convert an alkene to an epoxide?

Accepted Answer

meta-Chloroperoxybenzoic acid (MCPBA)

Question 10

During the acid-catalyzed opening of an epoxide, which carbon does the nucleophile preferentially attack?

Accepted Answer

The more substituted carbon

Question 11

Which of the following best explains why epoxides are more reactive toward nucleophilic attack than ethers?

Accepted Answer

Epoxides have significant ring strain, making them more reactive.

Question 12

What is the major product when 1,2-epoxycyclopentane is treated with methanol in the presence of acid?

Accepted Answer

trans-2-methoxycyclopentanol (mixture of enantiomers)

Question 13

Which of the following statements about the mass spectrometry of ethers is correct?

Accepted Answer

Ethers commonly undergo $$\alpha-$$cleavage to form resonance-stabilized oxonium ions.

Question 14

Which of the following is the correct order of reactivity for the cleavage of ethers by hydrogen halides?

Accepted Answer

$$\mathrm{HI \u003e HBr \u003e HCl}$$

Question 15

Which product is formed when a Grignard reagent reacts with an epoxide, followed by aqueous workup?

Accepted Answer

A primary alcohol with two additional carbons

Question 16

What is the main difference between the acid-catalyzed and base-catalyzed opening of epoxides?

Accepted Answer

Acid-catalyzed opening occurs at the more substituted carbon, while base-catalyzed opening occurs at the less substituted carbon.

Question 17

Which of the following best describes the product of the reaction between 1-hexene and methanol in the presence of mercuric acetate followed by sodium borohydride?

Accepted Answer

2-methoxyhexane (Markovnikov product)

Question 18

Which of the following is a correct statement about the oxidation of sulfides?

Accepted Answer

Sulfides can be oxidized to sulfoxides and further to sulfones.

Question 19

Which of the following best describes the selectivity of epoxidation with peroxyacids?

Accepted Answer

The most electron-rich double bond reacts fastest.

Ethers, Epoxides, and Sulfides: Structure, Synthesis, and Reactions

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