$\mathrm{C_4H_8O_2}$\newline\newline$\mathrm{O(CH_2)_2O(CH_2)_2}$

$\mathrm{CH_3CH_2Br}$\newline\newline$\mathrm{(CH_3)_3CO^-}$

$\mathrm{CH_3I}$\newline\newline$\mathrm{C_6H_5OH}$

$\mathrm{CH_2^+=CH-CH_2}$\newline\newline$\mathrm{CH_2=CH^+-CH_2}$

Question 1

Which of the following statements best explains why ethers generally have lower boiling points than alcohols of similar molecular weight?

Accepted Answer

Ethers cannot form hydrogen bonds with themselves, while alcohols can.

Question 2

What is the correct structural formula for 1,4-dioxane?

Accepted Answer

$\mathrm{C_4H_8O_2}$
ewline
ewline$\mathrm{O(CH_2)_2O(CH_2)_2}$

Question 3

Which of the following is the correct IUPAC name for the compound with the formula $\mathrm{CH_3OCH_2CH_3}$?

Accepted Answer

Methoxyethane

Question 4

In the Williamson ether synthesis, which pair of reactants would best produce tert-butyl ethyl ether?

Accepted Answer

$\mathrm{CH_3CH_2Br}$
ewline
ewline$\mathrm{(CH_3)_3CO^-}$

Question 5

When methyl phenyl ether (anisole) is cleaved by HI, which products are formed?

Accepted Answer

$\mathrm{CH_3I}$
ewline
ewline$\mathrm{C_6H_5OH}$

Question 6

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

Accepted Answer

mCPBA ($\mathrm{meta}$-chloroperoxybenzoic acid)

Question 7

A halohydrin reacts with base to form an epoxide. Which mechanism best describes this transformation?

Accepted Answer

Intramolecular SN2 reaction where the alkoxide attacks the adjacent carbon bearing the halide.

Question 8

Which product is formed when an epoxide reacts with a Grignard reagent ($\mathrm{RMgBr}$) under acidic workup?

Accepted Answer

A primary alcohol with two additional carbon atoms from the Grignard reagent.

Question 9

Which of the following alkene systems is cumulated?

Accepted Answer

$\mathrm{C=C=C}$

Question 10

Which carbocation is most stabilized by resonance?

Accepted Answer

Benzylic carbocation ($\mathrm{C_6H_5CH_2^+}$)

Question 11

In the reaction of 1,3-butadiene with HBr, which product is favored at low temperature?

Accepted Answer

1,2-addition product: $\mathrm{CH_2BrCH=CHCH_3}$

Question 12

Which resonance structure best represents the allylic cation $\mathrm{CH_2=CHCH_2^+}$?

Accepted Answer

$\mathrm{CH_2^+=CH-CH_2}$
ewline
ewline$\mathrm{CH_2=CH^+-CH_2}$

Question 13

Which Diels-Alder reaction will occur at a faster rate?

Accepted Answer

A reaction with a diene in the s-cis conformation and a dienophile with an electron-withdrawing group.

Question 14

According to the endo rule in Diels-Alder reactions, where will the electron-withdrawing group on the dienophile be located in the product?

Accepted Answer

In the endo position, oriented towards the diene's pi system.

Question 15

Which of the following compounds is aromatic according to Huckel's rule?

Accepted Answer

Benzene ($\mathrm{C_6H_6}$)

Question 16

Which heterocyclic compound is aromatic?

Accepted Answer

Pyrrole

Question 17

Which of the following is the correct formula for naphthalene?

Accepted Answer

$\mathrm{C_{10}H_8}$

Question 18

Which compound is antiaromatic?

Accepted Answer

Cyclobutadiene ($\mathrm{C_4H_4}$)

Question 19

Which of the following best explains why pyridine is more basic than pyrrole?

Accepted Answer

The lone pair on nitrogen in pyridine is not involved in the aromatic pi system, making it available for protonation.

Organic Chemistry Study Guide: Ethers, Conjugated Systems, Aromaticity

Study Guide - Practice Questions