Question 1

Consider the reaction coordinate diagram with points A, B, C, D, E, F, G, H, and I. Which letters correspond to the transition states in the reaction pathway?

Accepted Answer

B, D, F, and H

Question 2

Given the reaction coordinate diagram, which step of the reaction is the fastest?

Accepted Answer

The step with the lowest activation energy barrier

Question 3

Which of the following bases can deprotonate propanoic acid ($$pK_a = 4.88) in a $$reaction that favors product formation?

Accepted Answer

(i) $$CH_3O^-$$, (ii) $$NH_3$$, (iii) $$CH_3C\equiv C^-$$

Question 4

At which carbon would an electrophile attach in hex-1-en-5-yne, and why?

Accepted Answer

Carbon 1, due to the formation of a more stable carbocation.

Question 5

An unknown alkyne gives dodecanedioic acid after oxidative cleavage. Which structure is most likely for the unknown alkyne?

Accepted Answer

$$H_3C(CH_2$)_4C\equiv C(CH_2$)_4CH_3$$

Question 6

Which product is formed from the oxymercuration–demercuration of 1-ethyl-4-methylcyclohexene?

Accepted Answer

Trans-2-ethyl-4-methylcyclohexanol

Question 7

When 1-methylcyclohexene reacts with $$H_2SO_4$$ and $$H_2O$$, which product is expected?

Accepted Answer

2-methylcyclohexanol

Question 8

Why does ring opening occur in opposite directions in the two reactions shown, one with a tetraalkylammonium group and one with an ethoxy group?

Accepted Answer

Because the tetraalkylammonium group can stabilize positive charge, while the ethoxy group is a weaker electron donating group.

Question 9

What is the expected product when 4-ethylstyrene is treated with excess hot, concentrated potassium permanganate?

Accepted Answer

Benzoic acid and propanoic acid

Question 10

Which arrow-pushing mechanism correctly explains the regioselectivity and stereospecificity of halohydrin formation from styrene and $$Br_2 in $$water?

Accepted Answer

Formation of bromonium ion followed by nucleophilic attack of water at the more substituted carbon

Question 11

For the hydrogenation of 1,2-dimethylcyclohexene with $$H_2/Pt$, what is the major product including stereochemistry?

Accepted Answer

Trans-1,2-dimethylcyclohexane

Question 12

Which alkene will only generate 2-bromo-3,3-dimethylpentane after reaction with a suitable hydrohalic acid?

Accepted Answer

3,3-dimethyl-2-pentene

Question 13

What is the product when 3-methyl-1-butyne is treated with $$H_2$$ and $$Pd/C$$?

Accepted Answer

3-methylbutane

Question 14

Which acetylide ion and carbonyl compound can be used to synthesize 3,7-dimethyloct-4-yn-3-ol?

Accepted Answer

2,6-dimethylhept-3-yn-1-ide and acetaldehyde

Question 15

What are the products of but-1-yne when treated with (i) $$NaNH_2$$, (ii) $$HgSO_4/H_2SO_4$, H_2O$, and (iii) $$Sia_2BH$$, followed by H_2O_2$, OH$$^-$$?

Accepted Answer

(i) 1-butyne anion, (ii) 2-butanone, (iii) butanal

Question 16

Why does the $$S_N2$$ reaction of a 1° bromide by alkynide fail to give the desired product when the substrate contains an alcohol group?

Accepted Answer

Due to the presence of an acidic alcoholic proton in the substrate, an acid-base reaction will occur instead of a substitution reaction.

Question 17

Which of the following statements best explains why the bond dissociation energy of a C–Br bond is higher in a methyl bromide than in a benzyl bromide?

Accepted Answer

Because the benzyl radical is stabilized by resonance, making the C–Br bond easier to break.

Question 18

Which intermediate in the reaction coordinate diagram (A, C, E, G, I) is the most stable?

Accepted Answer

I

Question 19

Between intermediates E and G in the reaction coordinate diagram, which forms faster from G?

Accepted Answer

E forms faster from G if the activation energy from G to E is lower than from G to other intermediates.

Advanced General Chemistry: Reaction Mechanisms, Acid-Base Chemistry, and Organic Transformations

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