Enols and Enolates and Carbonyl Condensation Reactions Questions

Practice

Section A

Name___________________________________ PID_______________________

Please place name and PID on this paper , please show all mechanisms using curved arrows to show the movement of electrons between stable intermediaates and products.

M.C. questions are worth 2 points each

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Which of the following amines will react with cyclopentanone to form an enamine?

  1. (CH3)3N
  2. pyridine
  3. CH3CH2CH2CH2NH2
  4. (CH3)3CNH2
  5. none of the above
1)
2) What is the major organic product of the following reaction?2)

word image 311

A) I B) II C) III D) IV

3) Which of the following is a pyranose ring? A)B)3)

word image 312 word image 313

C) Both of these are pyranose rings. D) Neither of these is a pyranose ring.

4) What is the product of the following reaction? 4)

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A) I B) II C) III D) IV
5) Identify the correct sequence of substances in degree of oxidation.

A) alcohol → carboxylic acid → aldehyde B) carboxylic acid → aldehyde → alcohol

C) alcohol → aldehyde → carboxylic acid D) carboxylic acid → alcohol → aldehyde

5)
6) Cyclic acetals are used as protecting groups for ketones or aldehydes because they6)

are inert to all of the following reagents except

A) aqueous acid. B) oxidizing reagents.

C) reducing reagents. D) aqueous base.

7) What product is formed when the following compound is hydrolyzed with aqueous acid?7)

word image 314

A) I B) II C) III D) IV
8) Using 1H NMR spectroscopy, how can you tell the difference between an aldehyde and a ketone?

  1. A ketone has a signal around 200 ppm.
  2. An aldehyde has a proton signal between 9-10 ppm.
  3. A ketone has signals around 2-3 ppm.
  4. An aldehyde has a C-H stretch (one or two) between 2700-2830 cm-1.
8)
9) What IR absorption is characteristic of the C=O stretch in aldehydes?9)
A) 3300 cm-1 B) 3500 cm-1 C) 2950 cm-1 D) 1710 cm-1 E) 2250 cm-1
10) What is the product of the following reaction?10)

word image 430

A) I B) II C) III D) IV

11) Why can’t you use acidic conditions (such as aqueous hydrochloric acid) for the addition of a Grignard reagent to a ketone?

  1. Because the Grignard reagent won’t dissolve in aqueous solutions
  2. Because the Grignard reagent will react with the acid and be quenched
  3. Because the ketone will be protonated and thus unreactive
  4. Because the ketone will form an unreactive enol
11)
12) What class of organic product results when 1-heptyne is treated with a mixture of mercuric acetate in aqueous sulfuric acid?

  1. ketone
  2. carboxylic acid
  3. ether
  4. aldehyde
  5. diol
12)
13) Reaction of ethylmagnesium bromide with which of the following compounds yields a tertiary alcohol after quenching with aqueous acid? A) n-butyllithium

  1. (CH3)2CO
  2. CH3CHO
  3. ethylene oxide
  4. H2CO
13)
14) Which of the following synthetic routes works best for preparing 4-octene?

  1. 4-bromooctane + KOC(CH3)3
  2. CH3CH2CH2CH2MgBr + CH3CH2CH2CHO
  3. 4-bromooctane + NaOCH3
  4. CH3CH2CH=PPh3 + CH3CH2CH2CH2CHO
  5. CH3CH2CH2CH=PPh3 + CH3CH2CH2CHO
14)
15) What would you use to prepare the following ylide from the starting phosphonium salt?15)

word image 315

A) Triphenylphosphine B) 1-Bromo-2-methylpropane

C) Acetic acid D) Butyl lithium

16) What is the purpose of a silyl ether?

  1. To prevent the formation of carboxylic acids
  2. To protect esters from organometallic reagents and other reagents
  3. To protect ketones from organometallic reagents and other reagents
  4. To protect alcohols from organometallic reagents and other reagents
16)
17) What is the major organic product of the following reaction?17)

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A) B) C) D)

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18) Which of the following is the cyclic hemiacetal formed from 4-hydroxyheptanal?18)

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A) I B) II C) III D) IV E) V
19) What is the cyclic hemiacetal product formed from intramolecular cyclization of the following hydroxy aldehyde?19)

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A) I B) II C) IIID) IV
20) Classify the reaction below as an oxidation, a reduction, or neither.20)

(CH3)2CHCH2OH → (CH3)2CHCHO

A) reduction B) oxidation C) neither

2211 Test 4 Practice

Name__________________________________PID_____________

Please ensure your Name and PID is on this exam paper.

21. Show the products and give reaction mechanisms for the following, using curved arrows to indicate the flow of electrons using a minimum of 7 words to illustrate key points and intermediates A (10 points)

H

+

O

N

H

2

B. (6 points)

2

O

M

e

C

P

P

h

3

+

22. Show how you would make the target compound on the right form the starting compound on the left. Show reagents and conditions where appropriate, and the structures of important intermediate compounds. Do not show any (arrow pushing) mechanisms!!!!

a. (9 points)

O O

4-Steps

OEtH

O

Bonus. (7 points) Mechanism of the hemiacetal!

E

t

O

O

H

H

+

Answer Key

Testname: 2211 TEST 4A SPRING 18 SECTION 1

  1. E
  2. B
  3. B
  4. A 5) C
  5. A
  6. A
  7. B
  8. D 10) C
  9. B
  10. A
  11. B
  12. E
  13. D
  14. D
  15. B
  16. C
  17. B
  18. B

6

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