Question 1

Which of the following structures correctly represents 2,3-diethyl-2,3-dimethyloxirane?

Accepted Answer

A three-membered oxirane ring with an ethyl and a methyl group on both carbons 2 and 3.

Question 2

Which sequence of reagents would best convert methylcyclopentene to the target cyclopentyl ether shown below, using only alkenes or cycloalkenes with no more than six carbons?

Accepted Answer

(1) BH$$_3$$·THF; (2) H$$_2O$_2$$, HO$$^-$$; (3) NaH; (4) Allyl bromide; (5) MCPBA

Question 3

What is the best reagent to convert cyclohexanethiol (C$$_6H$_{11}SH) to $$cyclohexanesulfonic acid (C$$_6H$_{11}SO$_3H$$)?

Accepted Answer

HNO$$_3$$

Question 4

In the Sharpless asymmetric epoxidation of a geraniol derivative, which reagent acts as the oxidizing agent?

Accepted Answer

tert-Butyl hydroperoxide

Question 5

Which statement best explains how the Sharpless epoxidation can produce only one enantiomer of the product?

Accepted Answer

The chiral tartrate ester creates a chiral environment, favoring attack on one face of the alkene.

Question 6

Which of the following is the correct product of the alkoxymercuration reaction between 1-isopropyl-4-methylcyclohexene and ethanol in the presence of Hg(OAc)$$_2$$?

Accepted Answer

The Markovnikov addition product: ethoxy group on the more substituted carbon.

Question 7

Which condensed and skeletal structure pair correctly represents isobutyl isopropyl ether?

Accepted Answer

$$\mathrm{CH_2CH(CH_3$)OCH(CH_3$)_2}$$; skeletal: ether with isobutyl and isopropyl group

Question 8

Which alcohol would be used to synthesize 2-bromo-3-methylpentane using PBr$$_3$$?

Accepted Answer

3-methyl-2-pentanol

Question 9

What is the correct sequence of steps to synthesize 1-cyclopentylethan-1-ol from bromocyclopentane using Grignard reagents?

Accepted Answer

React bromocyclopentane with Mg/ether, then with acetaldehyde, followed by H$$_3O$^+$$ workup.

Question 10

What is the product of the following reaction: benzyl alcohol treated with TsCl, Et$$_3N$$, then NaCN in DMS?

Accepted Answer

Benzyl cyanide ($$\mathrm{C_6H_5CH_2CN})$$

Question 11

Which sequence of reagents would convert cis-3-methylcyclopentanol to trans-1-chloro-3-methylcyclopentane?

Accepted Answer

SOCl$$_2$$ followed by SN2 inversion

Question 12

What is the major product when 1,6-hexanediol is heated with H$$_2SO$_4$$?

Accepted Answer

Cyclohexyl ether

Question 13

Which structure corresponds to (S)-4-chloropent-4-en-2-ol?

Accepted Answer

A five-carbon chain with a chlorine on C4, a double bond between C4 and C5, and an OH on C2, with S configuration at C2.

Question 14

What is the mechanism for the synthesis of 1-butanethiol from thiourea and 1-chlorobutane under basic hydrolysis?

Accepted Answer

Nucleophilic substitution of Cl by thiourea, followed by hydrolysis to release butanethiol.

Question 15

Which reagent would selectively reduce the ester group in methyl cyclopentanecarboxylate to an alcohol, leaving the ketone group untouched?

Accepted Answer

LiAlH$$_4$$, then H$$_3O$^+$$

Question 16

Which of the following best describes the role of diethyl tartrate in the Sharpless asymmetric epoxidation?

Accepted Answer

It acts as a chiral ligand, controlling the stereochemistry of the epoxide formed.

Question 17

In the alkoxymercuration of an alkene, which intermediate is formed before the final product is obtained?

Accepted Answer

A mercurinium ion intermediate

Question 18

Which of the following is a correct application of Grignard reagents in organic synthesis?

Accepted Answer

Grignard reagents react with aldehydes to form secondary alcohols after acidic workup.

Organic Chemistry Study Guide: Synthesis, Mechanisms, and Nomenclature

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