Transcript Chapter 18 Carboxylic Acid Derivatives

Chapter 18
Carboxylic Acid Derivatives
Lecture 24
Chem 30B
Carboxyl Derivatives
• In this chapter, we study five classes of
organic compounds.
– Under the structural formula of each is a drawing
to help you see its relationship to the carboxyl
group.
O
RCCl
A n acid
chloride
-H2 O
O
RC-OH H-Cl
O O
RCOCR'
An acid
anhydride
-H2 O
O
O
RC-OH H-OCR'
O
RCOR'
An ester
-H2 O
O
RC-OH H-OR'
O
RCNH2
An amide
-H2 O
O
RC-OH H-NH2
RC N
A nitrile
-H2 O
HO H
RC=N
Th e enol of
an amide
Structure: Acid Chlorides
• The functional group of an acid halide is an acyl
group bonded to a halogen.
– The most common are the acid chlorides.
– To name, change the suffix -ic acid to -yl halide.
O
O
RCAn acyl
group
O
CH3 CCl
O
Cl
Ethan oyl ch loride Benzoyl chloride
(Acetyl ch loride)
Cl
Cl
O
Hexan edioyl ch loride
(Adip oyl chloride)
Sulfonyl Chlorides
– Replacement of -OH in a sulfonic acid by
-Cl gives a sulfonyl chloride.
O
CH3 SOH
O
Methanes ulfon ic
acid
O
CH3 SCl
O
Methanes ulfonyl ch loride
(Mesyl ch loride, MsCl)
O
H3 C
SOH
O
p-Toluen esulfon ic
acid
O
H3 C
SCl
O
p-Toluen esulfon yl chloride
(Tosyl chlorid e, TsCl)
Acid Anhydrides
• The functional group of an acid anhydride is
two acyl groups bonded to an oxygen atom.
– The anhydride may be symmetrical (two
identical acyl groups) or mixed (two different
acyl groups).
– To name, replace acid of the parent acid by
anhydride.
O O
O O
CH3 COCCH3
COC
Acetic anhydride
Benzoic anhydride
Acid Anhydrides
• Cyclic anhydrides are named from the
dicarboxylic acids from which they are
derived.
O
O
O
S u cci n ic
an h ydride
O
O
O
Male i c
an h ydride
O
O
O
Ph th al ic
an h ydride
Phosphoric Anhydrides
• A phosphoric anhydride contains two
phosphoryl groups bonded to an oxygen
atom.
O
O
O
-
HO- P-O- P-OH
O
O- P-O-P- O
-
O- OOH OH
Diph osph oric acid
Di ph os ph ate i on
(Pyroph os ph ori c aci d) (Pyroph os ph ate i on )
O
O
O
HO- P-O- P-O-P- OH
O- O- OTri ph osph oric acid
O
-
O
O
O- P-O-P- O-P- O
-
O- O- OTri ph osph ate ion
Esters
• The functional group of an ester is an acyl
group bonded to -OR or -OAr.
– Name the alkyl or aryl group bonded to oxygen
followed by the name of the acid.
– Change the suffix -ic acid to -ate.
O
O
O
O
O
Ethyl ethan oate
(Ethyl acetate)
Is op ropyl
ben zoate
EtO
OEt
O
D iethyl butaned ioate
(D ieth yl s uccin ate)
Esters
• Lactone: A cyclic ester.
– name the parent carboxylic acid, drop the
suffix -ic acid and add -olactone.

2
3
H3 C
O
O
1
O
3-Bu tanolactone
-Butyrolactone)

1
2
O
3 4
 
4-Bu tanolactone
-Bu tyrolacton e)



3
4
2
O
1
O
5 6


6-Hexan olacton e
-Cap rolactone)
Esters of Phosphoric Acid
• Phosphoric acid forms mono-, di-, and triesters.
• Name by giving the name of the alkyl or aryl
group(s) bonded to oxygen followed by the word
phosphate.
• In more complex phosphoric esters, it is common
to name the organic molecule and then indicate the
presence of the phosphoric ester by the word
phosphate or the prefix phospho-.
O
CH3 OPOH
OCH3
D imethyl
phosp hate
CHO
HO C-H
O
CH2 -O-P-OOGlyceraldeh yd e
3-phosph ate
CHO
HO
O
CH2 O-P-OO-
H3 C
N
Pyridoxal phosp hate
O
CO O
C O P OCH2 OPhosphoenolpyruvate
Amides
• IUPAC: drop -oic acid from the name of the parent
acid and add -amide. For the common name, drop
-ic of the parent name and add -amide.
• if the amide nitrogen is bonded to an alkyl or aryl
group, name the group and show its location on
nitrogen by N-.
O
CH3 CNH2
A cetamide
(a 1° amide)
O H
CH3 C-N
CH3
O CH3
H-C-N
CH3
N-Methylacetamide N ,N-D imethyl(a 2° amid e)
formamid e (DMF)
(a 3° amide)
Amides
• Lactams: A cyclic amides are called lactams.
– Name the parent carboxylic acid, drop the
suffix -ic acid and add -lactam.

2
3
H3 C
O
1
NH
3-Bu tanol actam
 -Butyrol actam)



3
4
2
O
1
NH
5 6


6-He xan olactam
 -C aprolactam)
Penicillins
– The penicillins are a family of -lactam
antibiotics.
HO
The penicillin s
differ in the
grou p bond ed
to the acyl carb on
O
H
H
S
NH
H2 N
-lactam
O
N
Amoxicillin
(a -lactam an tib iotic)
COOH
Cephalosporins
– The cephalosporins are also -lactam antibiotics.
The cephalosporins d iffer in the
group bonded to the acyl carbon an d
the s ide chain of the thiazin e rin g
O
NH2
H H
N
H
O
N
-lactam
Cep halexin
(Keflex)
S
Me
COOH
Imides
• The functional group of an imide is two
acyl groups bonded to nitrogen.
– Both succinimide and phthalimide are
cyclic imides.
O
NH
O
Succinimide
O
NH
O
Phthalimide
Nitriles
• The functional group of a nitrile is a cyano
group
– IUPAC names: name as an alkanenitrile.
– common names: drop the -ic acid and add
-onitrile.
CH3 C N
Ethanen itrile
(A cetonitrile)
C N
Benzon itrile
CH2 C N
Phenylethan enitrile
(Phenylacetonitrile)
Acidity of N-H bonds
• Amides are comparable in acidity to alcohols.
– Water-insoluble amides do not react with NaOH or
other alkali metal hydroxides to form water-soluble
salts.
• Sulfonamides and imides are more acidic than
amides.
O
CH3 CNH2
Acetamide
pKa 15-17
O
SNH2
O
O
NH
O
NH
O
O
Ben zenesu lfonamide Succinimide Phth alimide
pK a 10
p Ka 9.7
p Ka 8.3
Acidity of N-H bonds
•
Imides are more acidic than amides because
1. the electron-withdrawing inductive of the two
adjacent C=O groups weakens the N-H bond
2. the imide anion is stabilized by resonance
delocalization of the negative charge.
O
N
O
O
N
O
A resonance-stabilized an ion
O
N
O
Acidity of N-H
– Imides such as phthalimide readily dissolve
in aqueous NaOH as water-soluble salts.
O
NH +
O
pK a 8.3
(stron ge r
aci d)
O
N aOH
-
N Na
+
+
H2 O
O
(stron ge r
base )
(weak e r
base )
pK a 15.7
(weak e r
aci d)
Acidity of N-H
• Saccharin, an artificial sweetener, is an
imide.
The imide is sufficiently acidic that it reacts with
NaOH and aqueous NH3 to form water-soluble
salts. The ammonium salt is used to make liquid
Saccharin. Saccharin in solid form is the Ca2+ salt.
O
O
S
NH + NH3
O
O
S acch ari n
H2 O
S
N- NH4+
O
O
S acch ari n
A wat er-soluble
ammonium salt
Characteristic Reactions
• Nucleophilic acyl substitution: An additionelimination sequence resulting in
substitution of one nucleophile for another.
O
O
R
C
+
Y
:Nu
R
O
C
Nu
R
C
+
Nu
Y
Te trah edral carbon yl S u bstitu tion
addi tion i n te rme diate
produ ct
:Y
Characteristic Reactions
– In the general reaction, we showed the
leaving group as an anion to illustrate an
important point about them: the weaker the
base, the better the leaving group.
O
R2 N-
RO-
RCO-
Increasing leaving ability
Increasing basicity
X-
Characteristic Reactions
– Halide ion is the weakest base and the best
leaving group; acid halides are the most reactive
toward nucleophilic acyl substitution.
– Amide ion is the strongest base and the poorest
leaving group; amides are the least reactive
toward nucleophilic acyl substitution.
Reaction with H2O - Acid Chlorides
– Low-molecular-weight acid chlorides react
rapidly with water.
– Higher molecular-weight acid chlorides are
less soluble in water and react less readily.
O
CH3 CCl + H2 O
Acetyl chlorid e
O
CH3 COH + HCl
Reaction with H2O - Anhydrides
– Low-molecular-weight anhydrides react
readily with water to give two molecules of
carboxylic acid.
– Higher-molecular-weight anhydrides also
react with water, but less readily.
O O
CH3 COCCH3 + H2 O
Acetic an hydrid e
O
O
CH3 COH + HOCCH3
Reaction with H2O - Anhydrides
– Step 1: Addition of H2O to give a TCAI.
H +
O
CH3 -C- O-C- CH 3
O-H
H
H
O
O
CH3 -C- O-C- CH 3
+
O H
H
O-H
H
H
O
O
+
CH3 -C- O-C- CH 3 + H- O-H
O
H
H
Te trah edral carbon yl
addi tion i n te rme diate
Reaction with H2O - Anhydrides
–Step 2: Protonation followed
collapse of the TCAI.
H
H
+O
H
H
H
O
H
O
O
O
CH3 -C-O-C-CH3
O
H
H
H
+O
H
+ H
O
CH3 C O C CH3
H
H
H
O
CH3
O
H
O
C + O C
O
CH3
Reaction with H2O - Esters
• Esters are hydrolyzed only slowly, even in boiling
water.
– Hydrolysis becomes more rapid if they are heated with
either aqueous acid or base.
• Hydrolysis in aqueous acid is the reverse of
Fischer esterification.
– The role of the acid catalyst is to protonate the carbonyl
oxygen and increase its electrophilic character toward
attack by water (a weak nucleophile) to form a
tetrahedral carbonyl addition intermediate.
– Collapse of this intermediate gives the carboxylic acid
and alcohol.
Reaction with H2O - Esters
• Acid-catalyzed ester hydrolysis
R
O
C
OH
C
+
+
OCH3
H2 O
H
R
H
+
OH
OCH3
Tetrahed ral carbonyl
ad dition intermed iate
R
O
C
+
OH
CH3 OH
Reaction with H2O - Esters
• Saponification: The hydrolysis of an esters in
aqueous base.
– Each mole of ester hydrolyzed requires 1 mole of base
– For this reason, ester hydrolysis in aqueous base is said
to be base promoted.
O
RCOCH3 + NaOH
H2 O
O
-
RCO Na
+
+ CH3 OH
– Hydrolysis of an ester in aqueous base involves formation
of a tetrahedral carbonyl addition intermediate followed by
its collapse and proton transfer.
Reaction with H2O - Esters
– Step 1: Attack of hydroxide ion (a nucleophile) on
the carbonyl carbon (an electrophile).
– Step 2: Collapse of the TCAI.
– Step 3: Proton transfer to the alkoxide ion; this
step is irreversible and drives saponification to
completion.
O
O
O
(1)
(2)
R- C +
R- C-OCH3+ OH
R- C OCH3
O
OH
H
O
OCH3 (3) R- C + HOCH3
O
Reaction with H2O - Amides
• Hydrolysis of an amide in aqueous acid
requires one mole of acid per mole of amide.
– Reaction is driven to completion by the acidbase reaction between the amine or ammonia
and the acid.
O
O
N H2 + H2 O + HCl
Ph
2-Ph e n ylbu tan am ide
H2 O
heat
OH + N H4
Ph
2-Ph e n ylbu tan oi c aci d
+
Cl
-
Reaction with H2O - Amides
• Hydrolysis of an amide in aqueous base requires
one mole of base per mole of amide.
– Reaction is driven to completion by the
irreversible formation of the carboxylate salt.
O
CH3 CNH
N-Phen yleth anamide
(N-Phen ylacetamid e,
Acetan ilide)
+ NaOH
H2 O
heat
O
CH3 CO- Na+ + H2 N
Sodiu m
acetate
A niline
Reaction with H2O - Amides
– Step1: Protonation of the carbonyl oxygen gives a
resonance-stabilized cation intermediate.
O
+
R C NH2 + H O H
H
+H
O
R C NH2
H
H
O
R C
+
O
NH2
R C
+
NH2
Reso nance-stabil ized catio n i ntermed iate
+ H2 O
Reaction with H2O - Amides
– Step 2: Addition of water to the carbonyl carbon followed
by proton transfer gives a TCAI.
OH
+
R C NH2 +
OH
O H
H
R C NH2
O+
H
H
proton
transfe r from
O to N
OH
R C NH3 +
H
O
– Step 3: Collapse of the TCAI and proton transfer.
H
R C NH3 +
OH
H
+
O
R
O
C
OH
+
NH3
R
O
C
+
OH + NH4
Reaction with H2O - Nitriles
• The cyano group is hydrolyzed in aqueous acid to
a carboxyl group and ammonium ion.
Ph CH2 C N + 2 H2 O + H2 SO4
Phenylacetonitrile
H2 O
heat
O
+
Ph CH2 COH + NH4 HSO4
Ph enylacetic
Ammoniu m
acid
hydrogen s ulfate
– Protonation of the cyano nitrogen gives a cation
that reacts with water to give an imidic acid.
– Keto-enol tautomerism gives the amide.
+
R-C N + H2 O
H
OH
R-C NH
A n imidic acid
(en ol of an amide)
O
R-C-NH 2
An amide
Reaction with H2O - Nitriles
– Hydrolysis of a cyano group in aqueous base
gives a carboxylic anion and ammonia;
acidification converts the carboxylic anion to the
carboxylic acid.
CH3 ( CH2 ) 9 C N
Un decan enitrile
NaOH, H2 O
h eat
O
+
CH3 ( CH2 ) 9 CO Na + NH3
S od ium und ecanoate
HCl H2 O
O
CH3 ( CH2 ) 9 COH + NaCl + NH4 Cl
Und ecanoic acid
Reaction with H2O - Nitriles
Hydrolysis of nitriles is a valuable route to
carboxylic acids.
CH 3 ( CH2 ) 8 CH2 Cl KCN
ethanol,
1-C hlorode cane
water
CH3 ( CH2 ) 9 C N
Unde cane nitril e
OH
H2 SO4 , H2 O
heat
O
CH3 ( CH2 ) 9 COH
Unde canoic aci d
OH
CHO HCN , KCN
CN H2 SO 4 , H2 O
COOH
e th an ol,
heat
wate r
Be n z al de hyde
Be n z al de h yde cyan oh ydrin 2-H ydroxyph e n ylacetic aci d
(Man de l on itri le )
(Man de l ic acid)
(racemic)
(racemic)
Chapter 18
Carboxylic Acid Derivatives
Lecture 25
Chem 30B
Reaction with Alcohols
• Acid halides react with alcohols to give esters.
– Acid halides are so reactive toward even weak
nucleophiles such as alcohols that no catalyst is
necessary.
– If the alcohol or resulting ester is sensitive to
HCl, the reaction is carried out in the presence
of a 3° amine to neutralize the acid.
O
O
Cl + HO
Butanoyl
chloride
Cyclohexan ol
O
Cyclohexyl butan oate
+ HCl
Reaction with Alcohols
– Sulfonic acid esters are prepared by the reaction
of an alkane- or arenesulfonyl chloride with an
alcohol or phenol.
– The key point here is that OH- is transformed
into a sulfonic ester (a good leaving group) with
retention of configuration at the chiral center.
OT s
OH
+
(R)-2-Octanol
T sCl
pyridine
p-Toluenesulfonyl
chloride
(Tosyl chloride)
(R)-2-Octyl p-t oluenesulfonate
[(R)-2-Octyl tosylate]
Reaction with Alcohols
• Acid anhydrides react with alcohols to give one
mole of ester and one mole of a carboxylic acid.
O O
CH3 COCCH3 + HOCH2 CH 3
Ace ti c an h ydride Eth an ol
O
O
CH3 COCH2 CH3 + CH3 COH
Ace ti c aci d
Eth yl ace tate
– Cyclic anhydrides react with alcohols to give one
ester group and one carboxyl group.
O
O
O
O
Phth alic
anh yd rid e
+
O
OH
HO
O
2-Butan ol
(sec-Butyl alcohol)
(s ec-Bu tyl h yd rogen
phth alate
Reaction with Alcohols
– Aspirin is synthesized by treating salicylic acid
with acetic anhydride.
COOH
OH
O O
+ CH COCCH
3
3
Aceti c
2-H ydroxybe n z oi c an h ydride
aci d
COOH
(Sal icyli c aci d)
O
CH3
O
+
Ace tyls ali cyl ic aci d
(Aspi ri n )
O
CH 3 COH
Ace ti c aci d
Reaction with Alcohols
• Esters react with alcohols in the presence of an
acid catalyst in an equilibrium reaction called
transesterification.
O
+
OCH3
Me th yl prope n oate
(Me th yl acrylate)
(bp 81°C )
HO
1-Bu tan ol
(bp 117°C )
HCl
O
O
+ CH3 OH
Bu tyl prope n oate
Me th an ol
(Bu tyl acrylate)
(bp 65°C )
(bp 147°C )
Reaction with Ammonia, etc.
• Acid halides react with ammonia, 1° amines, and
2° amines to form amides.
– Two moles of the amine are required per mole of
acid chloride.
O
O
Cl + 2 NH3
Hexanoyl
chloride
Ammon ia
+
-
NH2 + NH4 Cl
Hexan amid e
Ammon ium
chloride
Reaction with Ammonia, etc.
• Acid anhydrides react with ammonia, and 1° and
2° amines to form amides.
– Two moles of ammonia or amine are required.
O O
CH3 COCCH3 + 2 NH3
Acetic
Ammon ia
anh yd rid e
O
O
+
+
CH
CO
NH
CH3 CNH2
3
4
Acetamid e Ammon ium
acetate
Reaction with Ammonia, etc.
• Esters react with ammonia and with 1° and
2° amines to form amides.
– Esters are less reactive than either acid halides or
acid anhydrides.
O
Ph
O
OEt + NH3
Ethyl p henylacetate
Ph
NH2 +
Phenylacetamide
• Amides do not react with ammonia or with
1° or 2° amines.
Et OH
Ethanol
Acid Chlorides with Salts
• Acid chlorides react with salts of carboxylic acids
to give anhydrides.
– Most commonly used are sodium or potassium
salts.
O
O
CH3 CCl + N a+ - OC
Ace tyl
ch loride
S odiu m
be n zoate
O O
CH3 COC
Ace ti c be n z oic
an h ydride
+
N a+ Cl
-
Chapter 18
Carboxylic Acid Derivatives
Lecture 26
Chem 30B
Interconversions of Acid
Derivatives
Reaction with Grignard Reagents
1. Addition of 1 mole of RMgX to the carbonyl
carbon of an ester gives a TCAI.
2. Collapse of the TCAI gives a ketone (an
aldehyde from a formic ester).
1
O
2
CH3 -C-OCH3 + R MgX
1
O [MgX]
CH3 -C
+
OCH3
R 2
A magnesiu m s alt
(a tetrahed ral carbonyl
addition intermediate)
O
+
CH3 -C + CH3 O [ MgX]
R
A ketone
Reaction with Grignard Reagents
– Treating a formic ester with two moles of
Grignard reagent followed by hydrolysis in
aqueous acid gives a 2° alcohol.
O
HCOCH3 + 2RMgX
An ester of
formic acid
OH
magnesium H O, HCl
2
alkoxide
HC-R + CH3 OH
salt
R
A 2° alcohol
Reaction with Grignard Reagents
– Treating an ester other than formic with a
Grignard reagent followed by hydrolysis in
aqueous acid gives a 3° alcohol.
O
CH3 COCH3 + 2RMgX
An ester of any acid
other than formic acid
magnesium
H2 O, HCl
alkoxide
salt
OH
CH3 C-R + CH3 OH
R
A 3° alcohol
Reaction with Grignard Reagents
3. Reaction of the ketone with a second mole
of RMgX gives a second TCAI.
4. Treatment with aqueous acid gives the
alcohol.
3
O
CH3 -C
R
A k eton e
-
O [MgX]
3
+ R
MgX
+
CH3 -C-R
R
Magnesiu m salt
OH
H2 O, HCl
(4)
CH3 -C-R
R
A 3° alcohol
Reactions with RLi
• Organolithium compounds are even more
powerful nucleophiles than Grignard
reagents.
– They react with esters to give the same types of
2° and 3° alcohols as do Grignard reagents
– and often in higher yields.
O
RCOCH3
1 . 2 R' Li
2 . H2 O, HCl
OH
R- C-R' + CH3 OH
R'
Gilman Reagents
• Acid chlorides at -78°C react with Gilman
reagents to give ketones.
– Under these conditions, the TCAI is stable, and it
is not until acid hydrolysis that the ketone is
liberated.
O
O
1 . ( CH3 ) 2 CuLi, eth er, -78°C
Cl 2 . H O
2
Pe n tan oyl ch l ori de
2-H exan on e
Gilman Reagents
– Gilman reagents react only with acid
chlorides.
– They do not react with acid anhydrides,
esters, amides or nitriles under the conditions
described.
O
H 3 CO
O
1 . ( CH3 ) 2 CuLi, eth er, -78°C
Cl 2 . H O
2
O
H 3 CO
O
Reduction - Esters by LiAlH4
• Most reductions of carbonyl compounds now
use hydride reducing agents.
– Esters are reduced by LiAlH4 to two alcohols.
– The alcohol derived from the carbonyl group is
primary.
O
Ph
OCH3
Me th yl 2-ph en yl propan oate
(race mic)
1 . LiA lH4 , e t he r
2 . H2 O, HCl
Ph
OH + CH3 OH
2-Ph e n yl-1propan ol
(race mic)
Me th an ol
Reduction - Esters by LiAlH4
• Reduction occurs in three steps plus workup:
– Steps 1 and 2 reduce the ester to an aldehyde.
O
R C OR' +
H
(1)
O
R C OR'
(2)
H
O
R C
+
OR'
H
A tetrahedral carbonyl
addition intermediate
– Step 3: Reduction of the aldehyde followed by work-up
gives a 1° alcohol derived from the carbonyl group.
O
R C
H
+ H
(3)
O
R C H
H
OH
(4)
R C H
H
A 1° alcohol
Reduction - Esters by NaBH4
• NaBH4 does not normally reduce esters, but
it does reduce aldehydes and ketones.
• Selective reduction is often possible by the
proper choice of reducing agents and
experimental conditions.
O
O
OEt
NaBH4
OH O
EtOH
OEt
(racemic)
Reduction - Esters by DIBALH
• Diisobutylaluminum hydride at -78°C
selectively reduces an ester to an aldehyde.
– At -78°C, the TCAI does not collapse and it is
not until hydrolysis in aqueous acid that the
carbonyl group of the aldehyde is liberated.
O
1 . DIBALH , toluen e, -78°C
OCH3
2 . H2 O, HCl
Me th yl h e xan oate
O
H + CH3 OH
He xan al
Reduction - Amides by LiAlH4
• LiAlH4 reduction of an amide gives a 1°,
2°, or 3° amine, depending on the degree
of substitution of the amide.
O
NH2
Octanamide
1 . LiAlH4
2 . H2 O
NH2
1-Octanamine
O
NMe2 1 . LiAlH4
2 . H2 O
N,N -D imethylben zamide
NMe2
N ,N-D imeth ylb enzylamine
Reduction - Amides by LiAlH4
• The mechanism is divided into 4 steps:
– Step 1: Transfer of a hydride ion to the
carbonyl carbon.
– Step 2: A Lewis acid-base reaction and
formation of an oxygen-aluminum bond.
O
(1)
R C NH2 + H AlH3
O
R C NH2 + AlH3
H
(2)
AlH3
O
R C NH2
H
Reduction - Amides by LiAlH4
– Step 3: Redistribution of electrons and ejection
of H3AlO- gives an iminium ion.
– Step 4: Transfer of a second hydride ion to the
iminium ion completes the reduction to the
amine.
O
H
AlH3
R C N H
H H
(3)
R C N H
H H
An iminium ion
(4)
R-CH2 -NH2
A 1° amine
Reduction - Nitriles by LiAlH4
The cyano group of a nitrile is reduced by LiAlH4 to
a 1° amine.
1 . LiA lH4
CH3 CH= CH( CH 2 ) 4 C N
2 . H2 O
6-O cte n en i tri le
CH3 CH= CH ( CH2 ) 4 CH2 N H2
6-O cte n -1-am in e
Interconversions
Problem: Show reagents and experimental
conditions to bring about each reaction.
O
Ph
Cl
(a)
(b )
O
Ph
OH
Ph enylacetic
acid
O
O
(d )
Ph
(c)
(e)
Ph
OMe
(g)
(f)
Ph
OH
NH2
(h )
Ph
NH2