Chapter 20-Carboxylic Acids and their Derivatives

Question 1

Suffix for Carboxylic Acid (IUPAC Nomenclature)

Answer 1

“-oic acid”

Question 2

What geometry do carboxylic acids have?

Answer 2

Trigonal Planar

Question 3

Considering carboxylics are soluble in polar solvents…when do they become amphiphilic (hydrophobic)?

Answer 3

Amphiphilic when chain is longer than 4 carbons.

Question 4

What is a carboxylate ion? (Hint: Draw it out!)

Answer 4

Question 5

Suffix for Carboxylate ion (IUPAC Nomenclature)

Answer 5

“-oate”

Question 6

pKa of Carboxylic Acids

Answer 6

~4-5

Question 7

True or False: Out of ALL of the organic functional groups carboxylic acids are the WEAKEST acids.

Answer 7

False, they are still weaker acids, but they are the strongest out of all of the functional groups.

Question 8

Do electron withdrawing groups (EWG) or electron donating groups (EDG) increase the acidity of Carboxylic Acids?

Answer 8

EWGs in crease the acidity.

Question 9

What are TWO oxidative cleavage routes to make carboxylic acids? (Hint: Think back to Organic Chemistry I!)

Answer 9

-KMnO4 w/ H2O and heat
-Ozonolysis (1) O3, 2) H2O)

Question 10

Name the TWO conditions in STRONG oxidation that an alcohol group must meet in order to form a carboxylic acid? (Hint: Think back to the first unit or two from this semester!)

Answer 10

1) Na2Cr2O7
2) H2SO4, H2O

Question 11

Name the two reagents used after forming the grignard reagent in order to form a carboxylic acid?

Answer 11

-CO2
-H3O+

Question 12

Provide a saponification mechanism for the following reaction.

Answer 12

Question 13

What reagents can be used to reduce a carboxylic acid to an alcohol?

Answer 13

LAH and H3O+

Question 14

What is the first thing the carboxylic acid can become in reduction? What is the second thing?

Answer 14

1) Aldehyde
2) Alcohol

Question 15

What is the othe reactant that can be used in place of LAH in reduction? Why is it a good subsitute for the LAH reagent?

Answer 15

BH3 (w/ THF) can be used. BH3 is chemoselctive for the carboxylic acid so therefore it will always react with the acid and will not react with an ester.

Question 16

Using Fischer Esterfication. Provide the mechanism for the following reaction.

Answer 16

Question 17

What is the poor route of making an amide from a carboxylic acid?

Answer 17

Forming an ammonium carboxylate salt than heating it to well above 100 degrees Celcius.

Question 18

What is the better route of synthesizing an amide from a carboxylic acid?

Answer 18

The use of an acid chloride.

Question 19

Recall: How do you prepare an acid chloride?

Answer 19

Transform a carboxylic acid with SOCl2 to make an acid chloride.

Question 20

Provide the first part of the mechanism of preparing an acid chloride.

Answer 20

Question 21

Provide the second part of the mechanism of preparing an acid chloride. What is the mechanism called?

Answer 21

Nucleophilic Acyl Substituion

Question 22

What are the five carboxylic acid derivatives?

Answer 22

-Acid Halide
-Acid Anhydride
-Ester
-Amide
-Nitrile

Question 23

What is the suffix change from a carboxylic acid (“-ic acid”) to an Acid Halide?

Answer 23

“-yl halide”

Question 24

What is the suffix change from a carboxylic acid (“-ic acid”) to an Anhydride?

Answer 24

“-Anhydride”

Question 25

What is the suffix change from a carboxylic acid ("-ic acid") to an Ester?

Answer 25

"-ate"

Question 26

What is the suffix change from a carboxylic acid ("-ic acid") to an Amide?

Answer 26

"-amide"

Question 27

What is the suffix change from a carboxylic acid ("-ic acid") to an Nitrile?

Answer 27

"-onitrile"

Question 28

Label the following from a scale 1-4, 1 being the least reactive and 4 being the most reaction: -Acid Halide -Ester -Anhydride -Amide

Answer 28

1-Amide 2-Ester 3-Anhydride 4-Acid Halide

Question 29

Define Nucleophilic Acyl Substitution.

Answer 29

The transfer of an acyl group to the attacking nucleophile.

Question 30

Most of the reactions are the same, and because I know you and I, and the whole world would be happier not rewriting this several billion times. Provide the general mechanism for the base conditions of these reactions.

Answer 30

Question 31

Howdy! Again, I know you don't want to rewrite this mechanism a million times. Guess what? Nor do I! Let's make this easier. Provide the general mechanism for the acid conditions of these reactions.

Answer 31

Question 32

Is a base a poor or strong nucleophile? Is an acid a poor or strong nucleophile?

Answer 32

A base is always, with a few exceptions, a strong nucleophile. An acid is also, always , with a few exception, a poor nucleophile.

Question 33

Rate the following leaving groups on a scale from 1-4, 1 being the least basic, and 4 being the most basic: >Chloride >Carboxylate >-OR >-NH2

Answer 33

1: Chloride 2: Carboxylate 3: -OR 4: -NH2

Question 34

How do you attempt to have an unfavorable reaction order?

Answer 34

-Add excess of nucleophile or use a stronger one. -Add heat -Activate Carbonyl (Make stronger electrophile, protonate using an acid)

Question 35

Because I feel that in my bones she will make this extra credit. Provide the mechanism for acetal CoA.

Answer 35