Carboxylic Acids and Derivatives **

Question 1

Amides

Answer 1

are the condensation products of carboxylic acids and ammonia or amines. they are given the suffix -amide. the alkyl groups on a substituted amide are written at the beginning of the name with the prefix N-. Lactams are cyclic amides. They are named by the greek letter they of the carbon they form on.

Question 2

esters

Answer 2

are the condensation products of carboxylic acids with alcohols (Fischer esterification). theya re given the suffix -oate. The esterifying group is written as a substituent, without a number.

Question 3

Lactones

Answer 3

are cyclic esters. Lactones are named by the number of carbons in the ring and the greek letter of the carbon forming the bond with the oxygen.

Question 4

Triacylglycerols,

Answer 4

which are a form of fat storage, include three ester bonds between glycerol and fatty acids. Saponification is the breakdown of fat using a strong base to form soap (salt of long chain carboxylic).

Question 5

anhydrides

Answer 5

are the condensation dimers of carboxylic acids. symmetric anhydrides are named for the parent carboxylic acid, followed by anhydride. Asymmetric anhydride are named by listing the parent carboxylic acids alphabetically, followed ed by anhydride. Some cyclic anhydrides can be synthesized by heating dioic acids. Five ore six membered rings are generally stable.

Question 6

In nucleophilic substitution reactions, anhydrides are more

Answer 6

reactive than esters, which are more reactive than amides.

Question 7

Steric hindrance

Answer 7

describes when a reeaction cannot proceed (or significantly slow) because of usbstituents crowding the reactive site.

Question 8

Protecting groups

Answer 8

such as acetals, can be used to increase steric hindrance or otherwise decrease reactivity of a particular portion of a molecule.

Question 9

Induction

Answer 9

refers to uneven distribution of charge across a sigma bond because difference in electronegativity. The more electronegative groups in a carbonyl-containing compound, the greater its reactivity.

Question 10

Conjugation

Answer 10

refers to the presence of alternating single and multiple bonds, which delocalized pi electron clouds above and below the plane of the molecule. Conjugated carbonyl–containing compounds are more reactive because they can stabilize their transition states.

Question 11

electron resonance

Answer 11

through the unhybridized p orbitals, increasing stability.

Question 12

increase strain in a molecule can

Answer 12

make it more reactive. beta-lactams are prone to hydrolysis because they have significant ring strain. Ring strain is due to the torsional strain from eclipsing interactions and angle strain from compressing bond angles below 109.5.

Question 13

All carboxylic acid derivatives can undergo

Answer 13

nucleophilic substitution reactions. the rates at which they do so are determined by their relative reactivities.

Question 14

Anhydrides can be cleaved by the addition of a

Answer 14

nucleophile. Addition of ammonia or a amine results in an amide and a carboxylic acid. Addition of an alcohol results in a ester and a carboxylic acid. addition of water results in two carboxylic acids.

Question 15

Transesterification

Answer 15

is the exchange of one esterifying group for another on an ester. The attacking nucleophile is an alcohol.

Question 16

Amides

Answer 16

can be hydrolyzed to carboxylic acids under strongly acidic or basic conditions. The attacking nucleophile is a water or the hydroxide anion.