Question 1

Which of the following is the correct product for the Wolff–Kishner reduction of the given ketone: $$\mathrm{C_6H_{11}COC_6H_5}$$ with $$\mathrm{H_2NNH_2}$$, $$\mathrm{KOH}$$, $$\mathrm{HO^-}$$, and heat?

Accepted Answer

Cyclohexylbenzene ($$\mathrm{C_6H_{11}C_6H_5})$$

Question 2

Is the formation of a cyanohydrin possible by adding a ketone to a solution of $$\mathrm{KCN}$$?

Accepted Answer

Yes, a cyanohydrin can be formed in basic conditions.

Question 3

Which synthetic approach correctly uses a protecting group to prepare the target alcohol from the given starting material (cyclopentanone with a hydroxyl group)?

Accepted Answer

Protect the alcohol with tert-butyldimethylsilyl chloride and imidazole, react with $$\mathrm{CH_3MgBr}$$, then deprotect with acid.

Question 4

What is the correct IUPAC name for the compound shown below?

$$\mathrm{PhCH(CH_3$)CHO}$$

Accepted Answer

2-phenylpropanal

Question 5

Which reactants are needed for Fischer esterification to form isopropyl propionate?

Accepted Answer

Propionic acid ($$\mathrm{CH_3CH_2COOH}) $$and isopropanol ($$\mathrm{(CH_3$)_2CHOH})$$

Question 6

Given the following compounds, which will undergo decarboxylation upon heating?

(i) $$\mathrm{CH_3COCH_2COCH_3}
(ii$$) $$\mathrm{CH_3COCH_2COOH}$$

Accepted Answer

(i) The compound will not undergo decarboxylation upon heating. (ii) The compound will undergo decarboxylation upon heating.

Question 7

Which set of products is expected from the acid-catalyzed esterification of isobutyric acid ($$\mathrm{(CH_3$)_2CHCOOH}) $$and ethanol ($$\mathrm{CH_3CH_2OH}$$)?

Accepted Answer

Isobutyl ethanoate ($$\mathrm{(CH_3$)_2CHCOOCH_2CH_3}) $$and water ($$\mathrm{H_2O})$$

Question 8

Which four-step synthesis involving an organocuprate reagent would convert 1-pentenylcyclopentane to cyclopentanone?

Accepted Answer

Hydroboration-oxidation, PCC oxidation, SOCl$$_2$$ conversion, organocuprate addition

Question 9

Which structure correctly represents 4,4-diethylhexanenitrile?

Accepted Answer

A hexanenitrile chain with two ethyl groups at the 4-position

Question 10

Why does the carbonyl oxygen of the ester attack the aluminum of DIBAL-H instead of the alkoxy oxygen?

Accepted Answer

The resonance hybrid of the ester shows that the carbonyl oxygen is more nucleophilic than the alkoxy oxygen.

Question 11

A Russian chemist investigated the hydrolysis of an ester by a hydroxide ion and discovered that the alkyl $$\mathrm{C-O}$$ bond remains intact while the acyl $$\mathrm{C-O}$$ bond breaks. What is the product of the hydrolysis of ethyl acetate labeled with $$^{18}O at $$the carbonyl oxygen?

Accepted Answer

Acetate ion with $$^{18}O $$and ethanol

Question 12

Which structure matches the compound phenyl N-ethyl carbamate?

Accepted Answer

A benzene ring attached to a carbamate group ($$\mathrm{NHCOOEt})$$

Question 13

Which of the following compounds is more reactive toward hydrolysis: benzyl propionate or phenyl propionate?

Accepted Answer

Benzyl propionate

Question 14

Why do only methyl ketones form haloforms in the haloform reaction?

Accepted Answer

Because only methyl can have three halogen atoms on its $$\alpha-$$carbon to form a good leaving group, only methyl ketones can form a haloform.

Question 15

Which resonance structures are correct for the enolate ion produced by deprotonation of methyl acetoacetate?

Accepted Answer

Resonance forms with negative charge delocalized between the two carbonyl oxygens and the $$\alpha-$$carbon

Question 16

In the following reaction sequence, what is the major product after alkylation of the enolate generated from cyclohexanone?

$$\mathrm{LDA, THF, -78^\circ C}$$, $$\mathrm{CH_3CH_2Br}$$

Accepted Answer

2-ethylcyclohexanone

Question 17

Which sequence of reagents will convert ethyl acetoacetate to cyclohexanone?

Accepted Answer

Alkylation with cyclohexyl bromide, followed by hydrolysis and decarboxylation

Organic Chemistry: Advanced Reaction Mechanisms, Synthesis, and Nomenclature Study Guide

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