CH 18 - Carboxylic Acid Derivatives

naming - acid halides

replace -ic acid with -yl chloride

naming - symmetrical anhydrides

replace “acid” with “anhydride”

naming - unsymmetrical anhydrides

list each acid (alphabetical order) followed by work “anhydride”

naming esters -

name -OR group as alkyl group followed by acyl portion as carboxylate

naming - cyclic esters

replace -oic acid with -olactone

naming - amides

name -NR2 groups as alkyl group (if present) and use preceding N- to indicate attachment to nitrogen, followed by acyl portion replacing

• ic acid with amide

naming - for cyclic amides

replace -oic acid with -olactam

naming - cyclic amides → for two acyl groups bonded to same nitrogen

(imide) replace -ic acid with -imide

for nitriles use ending

“nitrile” following name of parent alkane (including nitrile carbon)

where a-H is most acidic, pKa are

generally in mid 20s

• esters, 3 amides, nitriles

where most acidic is on N, pKa are

lower due to resonance and inductive effects

• 1 and 2 amides, imides

nucleophile acyl substitution

• can be acid-catalyzed or base-promoted

• nucleophile replace LG

nucleophile acyl substitution- in either acidic or basic, reactivity is determined by

leaving group ability and ability of substitutuent to donate electrons to C=O carbon

• substituent: amide < ester < anhydride < acid halide

• leaving ability: R2N < RO- < Rc=oO- < X-

hydrolysis =

cleavage with water

acid chloride + H2O →

carboxylic acid

• acidic or basic conditions

all carboxylic acid derivatives can be easily converted into

less reactive derivatives

• ester → amide but not vice versa

can also convert one derivative into a

different version of same derivative

• ethyl ester → methyl ester, transesterification

hydrolysis of a nitrile initially gives an

amide which can then undergo further hydrolysis

reaction of ester with Grignard reagent →

2 alcohol

ester of any acid + Grignard →

3 alcohol

reactions of acid chlorides with cooperate reagents

product is ketone

• chloride removed

reduction - esters (1.LiAlH4, ether 2. H2O, HCl) →

alcohols

NaBH4 does not

reduce esters

reduction of esters with DIBALDH

aldehydes

reduction of amides with LiAlH4

to amines

reduction of nitriles with LiAlH4 to

amines