Question 1

Which of the following statements best explains why the $$\pi$$ bond in an alkene is more reactive than the $$\sigma$$ bond?

Accepted Answer

The $$\pi$$ bond is formed from side-to-side overlap of p orbitals, making it weaker and more exposed to electrophilic attack.

Question 2

Which product is formed when 2-methyl-2-butene reacts with HBr in the absence of peroxides?

Accepted Answer

2-bromo-2-methylbutane

Question 3

According to Markovnikov's rule, when HCl is added to propene, which carbon does the Cl atom attach to?

Accepted Answer

The more substituted carbon

Question 4

Which of the following reagents will convert 1-methylcyclohexene to trans-1,2-dibromocyclohexane?

Accepted Answer

$$\mathrm{Br_2$}$$, CCl$$_4$$

Question 5

What is the major product when 1-butene reacts with $$\mathrm{Hg(OAc)_2}$$, $$\mathrm{H_2O}$$ followed by $$\mathrm{$$NaBH_4$$}$$?

Accepted Answer

2-butanol

Question 6

Which of the following best describes the stereochemistry of the product when cyclohexene is treated with $$\mathrm{$$OsO_4$$}$$ followed by $$\mathrm{$$NaHSO_3$$}$$?

Accepted Answer

A racemic mixture of cis-1,2-cyclohexanediol

Question 7

Which reagent(s) would you use to convert an alkene into an epoxide in a single step?

Accepted Answer

$$\mathrm{mCPBA}$$

Question 8

What is the expected product when 1-methylcyclohexene is treated with $$\mathrm{O_3$}$$ followed by $$(\mathrm{CH_3$})_2\mathrm{S}$$?

Accepted Answer

A ketone and an aldehyde

Question 9

Which of the following statements about anti-Markovnikov addition of HBr to alkenes is correct?

Accepted Answer

It requires the presence of peroxides (ROOR) to proceed.

Question 10

Which of the following best describes the product of syn dihydroxylation of cyclopentene using $$\mathrm{$$OsO_4$$}$$?

Accepted Answer

cis-1,2-cyclopentanediol

Question 11

Which of the following reagents will result in anti addition of two hydroxyl groups across an alkene?

Accepted Answer

$$\mathrm{mCPBA}$$ followed by $$\mathrm{H_3O^+}$$

Question 12

What is the product when 1,2-dimethylcyclohexene is treated with cold, dilute $$\mathrm{$$KMnO_4$$}$$?

Accepted Answer

cis-1,2-diol

Question 13

Which of the following is true about the addition of halogens (X$$_2) to $$alkenes?

Accepted Answer

The addition is anti, resulting in trans products.

Question 14

Which of the following best describes the product when 1-butene is treated with $$\mathrm{BH_3$} \cdot \mathrm{THF}$$ followed by $$\mathrm{H_2O_2}$$, $$\mathrm{NaOH}$$?

Accepted Answer

1-butanol

Question 15

Which of the following reagents would you use to hydrogenate an alkene to an alkane?

Accepted Answer

$$\mathrm{H_2$}$$, $$\mathrm{Pt}$$

Question 16

What is the product when cyclohexene is treated with $$\mathrm{Br_2$} in $$water?

Accepted Answer

trans-2-bromocyclohexanol

Question 17

Which of the following statements about ozonolysis of alkenes is correct?

Accepted Answer

Ozonolysis cleaves the double bond and can yield aldehydes, ketones, or carboxylic acids depending on the workup.

Question 18

Which of the following is a key difference between acid-catalyzed hydration and hydroboration-oxidation of alkenes?

Accepted Answer

Acid-catalyzed hydration follows Markovnikov's rule, while hydroboration-oxidation gives anti-Markovnikov alcohols.

Question 19

Which of the following best describes the product when cyclohexene is treated with $$\mathrm{mCPBA}$$ followed by $$\mathrm{H_3O^+}$$?

Accepted Answer

trans-1,2-cyclohexanediol

Chapter 8: Reactions of Alkenes – Mechanisms, Regioselectivity, and Stereochemistry

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