Q: Which of the following reagents would best reduce an ester to an aldehyde without further reduction to an alcohol?

$$1)\ \mathrm{DIBAL{-}H},\ -78^\circ\mathrm{C} \\ 2)\ \mathrm{H_3O^+}$$

Q: A chemist wants to convert a carboxylic acid to a primary alcohol. Which sequence of reagents would be most appropriate?

$$1)\ \mathrm{$$LiAlH_4$$,\ ether} \\ 2)\ \mathrm{H_3O^+}$$

Question 1

Which of the following reagents would best reduce an ester to an aldehyde without further reduction to an alcohol?

Accepted Answer

$$1)\ \mathrm{DIBAL{-}H},\ -78^\circ\mathrm{C} \ 2)\ \mathrm{H_3O^+}$$

Question 2

Which of the following is the correct order of leaving group ability from best to worst for the following groups: $$\mathrm{Cl^-}$$, $$\mathrm{O^-}$$, $$\mathrm{RCOO^-}$$, $$\mathrm{NH_2$^-}$$?

Accepted Answer

$$\mathrm{Cl^-} \u003e \mathrm{RCOO^-} \u003e \mathrm{O^-} \u003e \mathrm{NH_2$^-}$$

Question 3

Which of the following reagents would convert a primary alcohol to a bromide most efficiently?

Accepted Answer

$$\mathrm{$$PBr_3$$}$$

Question 4

Which of the following is the correct order of acidity (most acidic to least acidic) for the following compounds: $$p-$$nitrophenol, $$p-$$methoxyphenol, phenol, water, $$p-$$cresol?

Accepted Answer

$$p-$$nitrophenol \u003e phenol \u003e $$p-$$cresol \u003e water \u003e $$p-$$methoxyphenol

Question 5

Which of the following would react fastest with acetic anhydride?

Accepted Answer

Aniline ($$\mathrm{C_6H_5NH_2})$$

Question 6

A chemist wants to convert a carboxylic acid to a primary alcohol. Which sequence of reagents would be most appropriate?

Accepted Answer

$$1)\ \mathrm{$$LiAlH_4$$,\ ether} \ 2)\ \mathrm{H_3O^+}$$

Question 7

Which of the following best describes the product of the reaction of a ketone with $$\mathrm{NH_2OH} ($$hydroxylamine)?

Accepted Answer

An oxime

Question 8

Which reagent would selectively oxidize a 1,2-diol to two carbonyl compounds?

Accepted Answer

$$\mathrm{$$HIO_4$$}$$

Question 9

A Grignard reagent is prepared from bromobenzene and magnesium in ether. Which functional group will react with this Grignard reagent to give a secondary alcohol after acidic workup?

Accepted Answer

An aldehyde

Question 10

Which of the following sequences would convert a primary alcohol to a carboxylic acid?

Accepted Answer

$$1)\ \mathrm{$$KMnO_4$$,\ H_2O}$$

Question 11

Which of the following best describes the product of the reaction of an acid chloride with ammonia?

Accepted Answer

A primary amide

Question 12

Which of the following is the best method to prepare a methyl ester from a carboxylic acid?

Accepted Answer

$$\mathrm{CH_3OH}$$ and $$\mathrm{H^+}$$

Question 13

Which of the following is the correct order of reactivity toward nucleophilic acyl substitution: acid chloride, ester, amide, anhydride?

Accepted Answer

Acid chloride \u003e anhydride \u003e ester \u003e amide

Question 14

Which of the following would NOT be a suitable method for preparing an amide?

Accepted Answer

Reacting a carboxylic acid with ammonia directly

Question 15

Which of the following best describes the product of the reaction of a nitrile with $$1)\ \mathrm{$$LiAlH_4$$,\ ether} \ 2)\ \mathrm{H_3O^+}$$?

Accepted Answer

A primary amine

Question 16

Which of the following is the best method to convert a carboxylic acid to an acid chloride?

Accepted Answer

$$\mathrm{$$SOCl_2$$}$$

Question 17

Which of the following statements about the reaction of an ester with $$\mathrm{$$LiAlH_4$$} is $$correct?

Accepted Answer

The ester is reduced to a primary alcohol

Question 18

Which of the following is the best method to prepare a tertiary alcohol from a ketone?

Accepted Answer

Reacting the ketone with a Grignard reagent followed by acidic workup

Question 19

Which of the following best describes the product of the reaction of a 1,2-diol with $$\mathrm{$$HIO_4$$}$$?

Accepted Answer

Two carbonyl compounds

Question 20

Which of the following is the best method to convert a carboxylic acid to a methyl ketone?

Accepted Answer

$$1)\ \mathrm{$$SOCl_2$$} \ 2)\ \mathrm{CH_3MgBr,\ ether} \ 3)\ \mathrm{H_3O^+}$$

Organic Chemistry II Exam 2 Practice – Step-by-Step Guidance

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