Question 1

Which of the following reagents would best convert a primary alcohol to a primary alkyl bromide via a substitution reaction?

Accepted Answer

$$\mathrm{$$PBr_3$$}$$

Question 2

A student wants to synthesize an ether from a primary alkyl halide and an alcohol. Which reaction mechanism is most likely involved?

Accepted Answer

Williamson ether synthesis ($$\mathrm{R-X + R'O^- \rightarrow R-O-R'})$$

Question 3

Which of the following best describes the regiochemistry of HBr addition to propene in the presence of peroxides?

Accepted Answer

Anti-Markovnikov addition

Question 4

What is the major organic product when 2-methyl-2-butene reacts with $$\mathrm{Br_2$} in$$ $$\mathrm{$$CCl_4$$}$$?

Accepted Answer

A vicinal dibromide (anti addition across the double bond)

Question 5

Which reagent would you use to convert a terminal alkyne to a trans-alkene?

Accepted Answer

$$\mathrm{Na/NH_3$} ($$Birch reduction)

Question 6

A chemist wants to prepare a nitrile from a primary alkyl halide. Which reagent should be used?

Accepted Answer

$$\mathrm{NaCN}$$

Question 7

Which of the following statements about hydroboration-oxidation of alkenes is correct?

Accepted Answer

It results in anti-Markovnikov addition of water across the double bond.

Question 8

What is the product of ozonolysis of 1-methylcyclohexene followed by reductive workup ($$\mathrm{Zn/CH_3COOH}$$)?

Accepted Answer

A ketone and an aldehyde

Question 9

Which of the following best describes the outcome when 1-butyne is treated with $$\mathrm{H_2O, H_2SO_4}$$, and $$\mathrm{$$HgSO_4$$}$$?

Accepted Answer

A methyl ketone via Markovnikov hydration

Question 10

Which of the following is a correct statement about the halogenation of alkanes?

Accepted Answer

Bromination is more selective than chlorination.

Question 11

A student treats 2-bromopropane with $$\mathrm{NaOH} in $$ethanol. What is the major product?

Accepted Answer

Propene (via E2 elimination)

Question 12

Which of the following reagents would best convert a dihalide to an alkyne?

Accepted Answer

$$\mathrm{$$NaNH_2$$}$$

Question 13

What is the stereochemical outcome of the addition of $$\mathrm{Br_2$} to $$cyclohexene?

Accepted Answer

Trans-1,2-dibromocyclohexane (anti addition)

Question 14

Which of the following is the best method to synthesize a trans-1,2-diol from an alkene?

Accepted Answer

Epoxidation followed by acid-catalyzed hydrolysis

Question 15

Which of the following is a correct statement about the formation of tosylates from alcohols?

Accepted Answer

Tosylates are formed by reacting alcohols with tosyl chloride ($$\mathrm{TsCl}) $$and pyridine.

Question 16

A chemist wants to convert 1-butanol to 1-bromobutane. Which sequence of reagents would be most efficient?

Accepted Answer

$$\mathrm{$$PBr_3$$}$$

Question 17

Which of the following best describes the product of hydroboration-oxidation of 1-methylcyclopentene?

Accepted Answer

Trans-2-methylcyclopentanol (anti-Markovnikov alcohol)

Question 18

Which of the following is the correct product when 1-butyne is treated with $$\mathrm{Br_2$} in$$ $$\mathrm{$$CCl_4$$}$$?

Accepted Answer

Trans-1,2-dibromo-2-butene

Question 19

Which of the following best describes the outcome of permanganate oxidation of an alkene under cold, dilute conditions?

Accepted Answer

Formation of a vicinal diol (syn addition)

Question 20

Which of the following is a true statement about the halogenation of alkanes?

Accepted Answer

Bromine reacts more selectively than chlorine, favoring substitution at the most substituted carbon.

Summary of Key Organic Chemistry Reactions: Substitution, Elimination, Addition, and Radical Mechanisms

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