Question 1

Which of the following alkenes would form the most stable carbocation upon reaction with HBr (without rearrangement)?

Accepted Answer

$$\mathrm{(CH_3$)_2C=CH_2$}$$

Question 2

What is the oxidation number of the carbon marked with an asterisk (*) in the following molecule?

$$\mathrm{CH_3CH(OH)CH_2$^*CO_2H}$$

Accepted Answer

$$+1$$

Question 3

Which of the following alkenes has an E configuration?

Accepted Answer

$$\mathrm{CH_3CH=$$CHCH_3$$}$$

Question 4

Which of the following reagents would convert an alkene to a vicinal diol with syn stereochemistry?

Accepted Answer

$$\mathrm{$$OsO_4$$}$$, $$\mathrm{H_2O_2}$$

Question 5

A reaction of 2-bromobutane with $$\mathrm{$$NaOCH_3$$} in $$methanol yields a mixture of alkenes. Which mechanism best explains the formation of both E and Z isomers?

Accepted Answer

E2 elimination

Question 6

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

Accepted Answer

A secondary alcohol with anti-Markovnikov regiochemistry and syn addition

Question 7

Which of the following is the correct order of increasing acidity for the following species: $$\mathrm{CH_3CH_2OH}$$, $$\mathrm{CH_3COOH}$$, $$\mathrm{H_2O}$$?

Accepted Answer

$$\mathrm{CH_3CH_2OH} \u003c \mathrm{H_2O} \u003c \mathrm{CH_3COOH}$$

Question 8

Which of the following statements about the reaction of an alkene with $$\mathrm{Br_2$} in $$water is correct?

Accepted Answer

The major product is a bromohydrin formed via anti addition

Question 9

Which of the following best explains why tertiary carbocations are more stable than secondary or primary carbocations?

Accepted Answer

Hyperconjugation and inductive effects from surrounding alkyl groups

Question 10

In the acid-catalyzed hydration of 2-methylpropene, what is the major product?

Accepted Answer

2-methyl-2-propanol

Question 11

Which of the following is the conjugate base of acetic acid ($$\mathrm{CH_3COOH}$$)?

Accepted Answer

$$\mathrm{CH_3COO^-}$$

Question 12

Which of the following reagents would convert a terminal alkyne to a cis-alkene?

Accepted Answer

Lindlar's catalyst ($$\mathrm{H_2$, Pd/$$BaSO_4$$, quinoline})$$

Question 13

Which of the following best describes the stereochemical outcome of the reaction of cyclohexene with $$\mathrm{Br_2$} in$$ $$\mathrm{$$CCl_4$$}$$?

Accepted Answer

Trans-1,2-dibromocyclohexane is formed via anti addition

Question 14

Which of the following is the correct product for the ozonolysis (reductive workup) of 1-methylcyclohexene?

Accepted Answer

A ketone and an aldehyde

Question 15

Which of the following statements is true regarding the E2 elimination reaction?

Accepted Answer

It requires a strong base and a good leaving group, and the hydrogen and leaving group must be anti-coplanar

Question 16

Which of the following is the correct IUPAC name for the compound shown below?

$$\mathrm{CH_3CH_2CH=CHCH_2CH_3}$$

Accepted Answer

Hex-2-ene

Question 17

Which of the following best explains why $$\mathrm{H_2SO_4} is $$used as a catalyst in the hydration of alkenes?

Accepted Answer

It protonates the alkene to generate a more reactive carbocation intermediate

Question 18

Which of the following is the correct product for the reaction of 1-butyne with $$\mathrm{$$NaNH_2$$}$$ followed by $$\mathrm{CH_3I}$$?

Accepted Answer

$$\mathrm{CH_3CH_2C \equiv $$CCH_3$$}$$

Question 19

Which of the following is the correct mechanism for the acid-catalyzed dehydration of 2-butanol?

Accepted Answer

E1 elimination via carbocation intermediate

Organic Chemistry Exam III Study Guide: Mechanisms, Stereochemistry, Synthesis, and Acid-Base Chemistry

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