resumen reacciones qo ii

Learning Group Problems 547

• Alkynes to alkenes• Alkenes and alcohols• Alcohols and alkyl halides• Alkenes and alkyl halides• Alcohols and ethers• Alkenes, epoxides, and 1,2-diols• Alkanes to alkyl halides• Alcohol silyl protecting group• Alcohols to carbonyl compounds

OHOH

(1) OsO4(2) NaHSO3(syn)

(1) Li, EtNH2(2) NH4

!

(anti) Markovnikov(1) Hg(OAc)2,THF/H2O(2) NaBH4orH2O, HA cat.

NaH or Na", K"

TsCl orMsCl, etc.

pyr

HA,heat

RO–, E2 elim.(best if RX is

2" or 3°, oruse bulky RO–)

I. HX(1" or 3")or if 1" or 2"II. PBr3orIII. SOCl2

HO–

(1" RX)orH2O(3" RX)

HX(Markov.)

HBr, ROOR,# (Anti-Markov.)

Br2, h$ or #(best if RH is 3")

Anti-Markovnikov(1) BH3:THF(2) H2O2, HO–

RCO3HC C

ONu:

H2O, HA or HO–

(anti)

TBSClimidazole

F–

H2, Ni2B (syn)or

CC

CC CC

C OHC

C O%C

C OTs(or Ms or Tf)

RX or ROTs(if RX or ROTs is 1")

R'O– (if RX or ROTs is 1")

C

C HC C XC C OR'C

OH

Nu

CC

C OTBSC

(a peroxy acid)

Oxidation/Reduction (Chapter 12)

(under acidic orbasic conditions)

C

O

Y

C

Y & H, R, or OH(also by alkeneoxidation, seeChapter 8)

Summary and Review Tools

Some Synthetic Connections of Alkenes, Alkynes, Alcohols, Alkyl Halides, and Ethers

Figure 11.4 Some synthetic connections of alkynes, alkenes, alcohols, alkyl halides, and ethers.

solom_c11_502-547hr2.qxd 15-10-2009 12:49 Page 547

Resumen de Reacciones Química Orgánica II, DC Angel A. Ramos O.

Summary of Reactions 583

Summary of Reactions

Summaries of reactions discussed in this chapter are shown below. Detailed conditions for thereactions that are summarized can be found in the chapter section where each is discussed.

Substrate

Aldehydes

Ketones

Esters

Carboxylicacids

(Hydrogen atoms in blue are added during the reaction workup bywater or aqueous acid.)

Reducing agent

NaBH4 LiAlH4 (LAH)

[H]

!

1. Carbonyl Reduction Reactions

• Aldehydes to primary alcohols• Ketones to secondary alcohols• Esters to alcohols• Carboxylic acids to primary alcohols

[H]

[H]

[H]

Synthetic Connections of Alcohols and Carbonyl Compounds

Substrate

Primary alcohols

Secondary alcohols

Tertiary alcohols

Oxidizing agent [O]

PCC H2CrO4 KMnO4

2. Alcohol Oxidation Reactions

• Primary alcohols to aldehydes• Primary alcohols to carboxylic acids• Secondary alcohols to ketones

[O]

[O]

[O]

R H

O

R R¿

O

R R¿

O

R R¿

O

R R¿

O

R OR¿

O

R OH

O

R H

O

R OH

O

R OH

O

R H

OH

H

R R¿

OH

H

R H

OH

H

R¿¬ OH

R R¿

OH

H

R H

OH

H

R H

OH

H

R R¿

OH

R–

R OH

R R¿

OH

solom_c12_548-584hr.qxd 1-10-2009 17:52 Page 583


584 Chapter 12 Alcohols from Carbonyl Compounds

Synthetic Connections of Alcohols and Carbonyl Compounds

(1)

(2) H3O! (or NH4!)

(2) H3O! (or NH4!)

(2) H3O! (or NH4!)

HR

XR

MgXR

Li ! LiXR

"R

Nu:

Nu # alkynyl group, or alkyl groupfrom Grignard or alkyllithium

reagent

(a substituted orunsubstituted oxirane

!

3. Carbon-Carbon Bond Forming Reactions

• Alkynide anion formation• Grignard reagent formation• Alkyllithium reagent formation• Nucleophilic addition to aldehydes and ketones• Nucleophilic addition to esters• Nucleophilic ring-opening of epoxides

NaNH2(or other

strong base)

2 Li

Mg in ether

(1)

(1) R OR¿

O

R¿(H) R–(H)

O

R¿(H) R–(H)

OH

Nu

R R¿¬ OHNu

OH

Nu

O

Nu

OH

See First Review Problem Set in WileyPLUS



Summary of Mechanisms 775

R"(

H)

R'

O

R"(

H)

R'

R"(

H)

R'

O

OH

R

R!

O!

!

AH

HO

H

H

R"(

H)

R'

O!R

"A

H

R"(

H)

R'

RO

H–

HO

H

AH

O

R"(

H)

R'

RO

HO

!

R"(

H)

R'

RO

RO

R"(

H)

R'O

OR

ROH

HR

"A

I. H

emia

ceta

l and

ace

tal f

orm

atio

n: r

eact

ion

with

alc

ohol

s

Man

y st

eps

are

near

ly th

e sa

me

in a

cid-

cata

lyze

d re

actio

ns o

f ald

ehyd

es a

nd k

eton

es w

ith a

lcoh

ols

and

amin

es.

Com

pare

the

mec

hani

sms

vert

ical

ly to

see

the

sim

ilarit

ies

and

diffe

renc

es.

Not

e di

ffere

nces

in c

ompl

etio

n of

the

mec

hani

sm fo

r ea

ch ty

pe o

f pro

duct

.

In a

ceta

l for

mat

ion,

the

oxon

ium

ion

isat

tack

ed b

y a

seco

nd a

lcoh

ol m

olec

ule.

In im

ine

form

atio

n, th

e pr

oton

on

the

initi

al im

iniu

m io

n is

rem

oved

,le

adin

g to

the

stab

le im

ine

prod

uct.

II. Im

ine

form

atio

n: r

eact

ion

with

pri

mar

y am

ines

Hem

iace

tal

Ace

tal

III. E

nam

ine

form

atio

n: r

eact

ion

with

sec

onda

ry a

min

es

SU

MM

AR

Y O

F M

EC

HA

NIS

MS

Ace

tals

, Im

ines

, and

Ena

min

es:

Com

mon

Mec

hani

stic

The

mes

in T

heir

Aci

d-ca

taly

zed

Form

atio

n fr

om A

ldeh

ydes

and

Ket

ones

R"(

H)

R'

O

R"(

H)

R'

R"(

H)

R'

O

NH

HH

R

R!

N!!

AH

HO

H

H

R"(

H)

R'

N!R

H

R"(

H)

R'

NR

"A

HH

R"(

H)

R'

RO

H"

HO

H

AH

N

H

N R"(

H)

R'

RO

H

Imin

e

Ena

min

e

"A

In e

nam

ine

form

atio

n, a

pro

ton

is r

emov

ed fr

om a

car

bon

adja

cent

to th

e im

iniu

m c

arbo

n (b

ecau

se n

o pr

oton

is a

vaila

ble

for

rem

oval

from

the

nitr

ogen

).

R"(

H)

R'

O

R"(

H)

R'

R"(

H)

R'

O

NH

HR

R

R!

N!!

AH

HO

H

R

R"(

H)

R'

N!N!

RR

R"(

H)

C

NR

R

"A

"

A

RH

R"(

H)

R'

RO

H"

HO

H

AH

N

R

N R"(

H)

R'

RO

H

R"(

H)

C H

RR



776 Chapter 16 Aldehydes and Ketones

SU

MM

AR

Y O

F M

EC

HA

NIS

MS

Nuc

leop

hilic

Add

ition

to A

ldeh

ydes

and

Ket

ones

Und

er B

asic

Con

ditio

ns

Gen

eral

ized

nuc

leop

hilic

add

ition

to a

n al

dehy

de o

r ke

tone

:

Pro

tona

tion

durin

gw

orku

p(in

mos

t rea

ctio

ns)

or b

y pr

otic

sol

vent

s

Ald

ehyd

e or

keto

ne

Exa

mpl

es:

Nuc

leop

hile

Hyd

ride

[e.g

., fr

omN

aBH

4 or

LiA

lH4

(LA

H)]

Tetr

ahed

ral i

nter

med

iate

R"(

H)

R'

Nu!

""

Nu

O

! H

Alk

ynid

e an

ion

! C

C

R

Alk

yllit

hium

Li

R

Gri

gnar

d re

agen

t

XM

g

R

OH

A

R"(

H)

R'

Pro

ductN

u

O

R"(

H)

R'H

R

O

R"(

H)

R'H

Alc

ohol

(with

C¬

C b

ond

form

atio

n)

Alc

ohol

(with

C¬

C b

ond

form

atio

n)

R

Alk

ynyl

alc

ohol

(C¬

C b

ond

form

atio

n)

O

R"(

H)

R'H H

Alc

ohol

(red

uctio

n)H

O

R"(

H)

R'H

H

O

R"(

H)

R'

R

O

R"(

H)

R'

A !

! !Li

"

R

O

R"(

H)

R'

!

CC

R

O

R"(

H)

R'

!

CC

R

O

H

R"(

H)

R'

Cya

nohy

drin

CN

O

R"(

H)

R'

CN

O

R"(

H)

R'

!

X!

Mg2"

Cya

nide

! C

N

!




SU

MM

AR

Y O

F M

EC

HA

NIS

MS

Nuc

leop

hilic

Add

ition

to A

ldeh

ydes

and

Ket

ones

Und

er B

asic

Con

ditio

ns

Gen

eral

ized

nuc

leop

hilic

add

ition

to a

n al

dehy

de o

r ke

tone

:

Pro

tona

tion

durin

gw

orku

p(in

mos

t rea

ctio

ns)

or b

y pr

otic

sol

vent

s

Ald

ehyd

e or

keto

ne

Exa

mpl

es(c

ontin

ued)

:O

xaph

osph

etan

ein

term

edia

teW

ittig

pre

para

tion

of a

lken

es(w

ith lo

ss o

f tri

phen

ylph

osph

ine

oxid

e [(

C6H

5)3P

O])

Nuc

leop

hile

Tetr

ahed

ral I

nter

med

iate

R"(

H)

R'

Pho

spho

rus

ylid

e

Eno

late

(see

Cha

pter

18)

Nu!

"P

(C6H

5)3

""

Nu

OO

HA

R"(

H)

R'

Pro

ductN

u

O

R"(

H)

R'H

b-H

ydro

xy a

nd a

,b-u

nsat

urat

edca

rbon

yl c

ompo

unds

A !

! R

1

R2

P(C

6H5)

3

R1

R2

R'

R'

R"(

H)

R2

R1

O R"(

H)

R4

O

R"(

H)

R'H

HR

3

O

R4

R4

R3

R3

HH

O

! A

R4

R'

(H)R

"

R3

OO

!

R4

O

R"(

H)

R'

HR

3

O!

!

!

(plu

s di

aste

reom

er)



778 Chapter 16 Aldehydes and Ketones

Syn

the

tic

Co

nn

ec

tio

ns

Som

e S

ynth

etic

Con

nect

ions

of A

ldeh

ydes

, Ket

ones

, and

Oth

er F

unct

iona

l Gro

ups

Cl

R¿

O

OR

OH

R–(

H)

R¿

SR

SR

R–(

H)

R¿

H

H

R–(

H)

R¿

OR

OR

R–(

H)

R¿

CC

R

OH

R–(

H)

R¿

CN

OH

R–(

H)

R¿ R

¿

R–(

H)

R3

R4

R¿

R–

R–

R¿ C

lR

¿

O

R"

R¿

O

HR

¿

O

OH

R¿

OO

R–

R¿

O

R–(

H)

R–(

H)

R¿

RN

RR

N

Clo

ckw

ise

from

cen

ter,

botto

m:

I. Pr

epar

atio

n of

ald

ehyd

esan

d ke

tone

s:

• Nitr

ile, e

ster

, acy

l

halid

e re

duct

ion

• Alc

ohol

oxi

datio

n• O

zono

lysi

s• F

riede

l–C

rafts

acy

latio

n• G

rigna

rd w

ith n

itrile

• Ace

tal a

nd h

emia

ceta

l h

ydro

lysi

s

II. R

eact

ions

of a

ldeh

ydes

and

keto

nes:

• Hem

iace

tal a

nd a

ceta

l for

mat

ion

• Thi

oace

tal f

orm

atio

n a

nd re

duct

ion

• Alk

ynid

e an

ion

addi

tion

• Nitr

ile a

dditi

on (

cyan

ohyd

rin fo

rmat

ion)

• Witt

ig s

ynth

esis

of a

lken

es• E

nam

ine

synt

hesi

s• I

min

e sy

nthe

sis

• Red

uctio

n to

alc

ohol

s (

left,

cen

ter)

RO

H,

cat.

HA

RO

H,

cat.

HA

RS

H (

2 eq

uiv.

),ca

t. H

A

H2O

,ca

t. H

A

H2O

,ca

t. H

A

H2,

Ran

ey N

i

H2O

,ca

t. H

A

R2N

H,

cat.

HA

RN

H2,

cat.

HA

(1)

R–M

gBr

or R

–Li

(2)

H3O

!

(1)

CH

R3 R

4 Br,

(C

6H5)

3P(2

) R

Li (

as s

tron

g ba

se)

(1)

ArH

, AlC

l 3;

(2)

HO

H(le

ads

to R

–=A

r)

(1)

LiA

lH(O

-t-B

u)3

(2)

H2O

SO

Cl 2

(1)

DIB

AL-

H(2

) H

2O

(1)

DIB

AL-

H(2

) H

2O

(1)

O3

(2)

Me 2

S(p

rodu

cts

depe

ndon

R g

roup

s)

CN

R¿

CN

R¿

(1)

RC

C

"

(2)

H3O

!

(1)

CN

"

(2)

H3O

!

(whe

n R

¿ bor

e a

hydr

ogen

for

rem

oval

)

(E)

and

(Z )

H2C

rO4

or K

MnO

4

NaB

H4;

or

(1)

LAH

; (2)

H2O

PC

C

R–

R¿

OH

OH

R¿

solom_c16_729-778hr.qxd 6-10-2009 14:43 78


818 Chapter 17 Carboxylic Acids and Their Derivatives

17.13 Summary of the Reactions of Carboxylic Acids and Their Derivatives

The reactions of carboxylic acids and their derivatives are summarized here. Many (but notall) of the reactions in this summary are acyl substitution reactions (they are principally thereactions referenced to Sections 17.5 and beyond). As you use this summary, you will findit helpful to also review Section 17.4, which presents the general nucleophilic addition–elim-ination mechanism for acyl substitution. It is instructive to relate aspects of the specific acylsubstitution reactions below to this general mechanism. In some cases proton transfer stepsare also involved, such as to make a leaving group more suitable by prior protonation or totransfer a proton to a stronger base at some point in a reaction, but in all acyl substitutionthe essential nucleophilic addition–elimination steps are identifiable.

Reactions of Carboxylic Acids

1. As acids (discussed in Sections 3.11 and 17.2C):

2. Reduction (discussed in Section 12.3):

3. Conversion to acyl chlorides (discussed in Section 17.5):

4. Conversion to esters (Fischer esterification) or lactones (discussed in Section 17.7A):

5. Conversion to amides (discussed in Section 17.8E):

O

RNH3!

OH

O

R O! NH4"

O

R NH2

! H2O

An amide

heat

R#! !OH H2OOR#OHR

O

R

OHA

SOCl2 or PCl5

R OH

O

R Cl

O

!(1) LiAlH4

(2) H3O+

R OH R OH

H HO

Na! ! H2O

Na! ! H2O ! CO2

R OH

OR O–

O

R O–

O

NaOH

NaHCO3

Nylon 6,6(A polyamide)

! H2O

n

O

NN

HO

H

Special Topic C continues our discussion of Step-Growth Polymers.

solom_c17_779-830hr1.qxd 14-10-2009 16:06 18


17.13 Summary of the Reactions of Carboxylic Acids and Their Derivatives 819

6. Decarboxylation (discussed in Section 17.10):

Reactions of Acyl Chlorides

1. Conversion (hydrolysis) to acids (discussed in Section 17.5B):

2. Conversion to anhydrides (discussed in Section 17.6A):

3. Conversion to esters (discussed in Section 17.7A):

4. Conversion to amides (discussed in Section 17.8B):

5. Conversion to ketones (Friedel–Crafts acylation, Section 15.7–15.9):

Cl

O

R! R!NHR" (excess)

NR!R"

O

R! R!NH2R"Cl

R! and/or R" may be H.

# $

pyridine

Cl

O

R! R!9 OH

OR!

O

R! Cl$ ! pyr-H#

Cl

O

R O

O

RO$

O

R! R!

O! ! Cl$

Cl

O

R! H2O

OH

O

R! HCl

heatR OH

O O+ c

R CH3

O

heat

CO2

+ cCO2HO OH

O O

OH

O

ClR

O R

O

!AlCl3

6. Conversion to aldehydes (discussed in Section 16.4C):

Reactions of Acid Anhydrides

1. Conversion (hydrolysis) to acids (discussed in Section 17.6B):

2. Conversion to esters (discussed in Sections 17.6B and 17.7A):

OR!R

O

OHR

O

! R!OH !R RO

O O

R

O

OH! H2O 2

R RO

O O

ClR

O

HR

O

!(1) LiAlH(t-BuO)3

(2) H3O+



820 Chapter 17 Carboxylic Acids and Their Derivatives

3. Conversion to amides (discussed in Section 17.8C):

4. Conversion to aryl ketones (Friedel–Crafts acylation, Sections 15.7–15.9):

Reactions of Esters

1. Hydrolysis (discussed in Section 17.7B):

2. Conversion to other esters: transesterification (discussed in Review Problem 17.10):

3. Conversion to amides (discussed in Section 17.8D):

4. Reaction with Grignard reagents (discussed in Section 12.8):

5. Reduction (discussed in Section 12.3):

OR!R

OR9CH2OH ! R!OH

(1) LiAlH4

(2) H3O+

!OR!R

O

2 R"MgXEt2O H3O

!

R99R" ! R!OMgX

R"

R99R"

R"

OHOMgX

HN!

R"

R# N! HR"

R#

R!O

R" and/or R# may be H.

OR!R

O

R

O

OR!R

O

OR"R

O ! R"OH ! R!OH

HA

OR!R

O

OHR

O ! H2O ! R!OH

OR!R

O

O$R

O ! OH$ ! R!OH

H2O

HA

!AlCl3

O R

!R OH

O

R RO

O O

NR R

O

R! and/or R" may be H.

!H

R!

R"

NR!

R"

!OH

O

R RO

O O



Key Terms and Concepts 821

Reactions of Amides

1. Hydrolysis (discussed in Section 17.8F):

2. Conversion to nitriles: dehydration (discussed in Section 17.8G):

Reactions of Nitriles

1. Hydrolysis to a carboxylic acid or carboxylate anion (Section 17.8H):

2. Reduction to an aldehyde with (i-Bu)2AlH (DIBAL-H, Section 16.4C):

3. Conversion to a ketone by a Grignard or organolithium reagent (Section 16.5B):

R

(1) R!MgBr or R!Li

(2) H3O!

OR9C#N !

R!

HR

(1) (i-Bu)2 AlH

(2) H2O

OR9C#N

H3O!

R9C#N

HO"

H2O, heatR9C#N

OHR

O

O"R

O

heat

R9C#NNH2R

OP4O10

heat("H2O)

R, R!, and/or R# may be H.

!NR

O

O"R

O

OH"H2O ! N

R#R#

R!R!H

!NR

O

OHR

O

H3O$H2O ! H9N9R!

R#R#

$R!

H

Key Terms and ConceptsThe key terms and concepts that are highlighted in bold, blue text within the chapter aredefined in the glossary (at the back of the book) and have hyperlinked definitions in theaccompanying WileyPLUS course (www.wileyplus.com).



868 Chapter 18 Reactions at the aa Carbon of Carbonyl Compounds

Sum

mar

y of

Mec

hani

sms

Eno

late

s: a

-Sub

stitu

tion

X

XX

O–

Car

bony

l

I. H

O–

in H

2O o

r R

OH

;

or R

O–

in R

OH

;U

sefu

l for

rea

ctio

ns in

volv

ing

ther

mod

ynam

ical

ly fa

vore

den

olat

es a

nd e

quili

briu

m p

rodu

ctco

ntro

l

II. L

DA

(lit

hium

diis

opro

pyla

mid

e)

in T

HF

or

DM

E;

Use

ful,

in g

ener

al, f

or fo

rmin

gen

olat

es in

apr

otic

sol

vent

s(e

spec

ially

kin

etic

ally

favo

red

enol

ates

and

dire

ct a

lkyl

atio

n)

Som

e gr

oups

that

incr

ease

a-h

ydro

gen

acid

ity

Gen

eral

Rea

ctio

n

Typi

cal b

ases

(– :A

)an

d so

lven

ts fo

ren

olat

e fo

rmat

ion

Pos

sibl

e el

ectr

ophi

les

(E–A

)P

rodu

ct(s

)

O

R

OA

–

A–

RR

Ha

d+

d–

H

Nitr

ile(c

yano

gro

up)

(and

in g

ener

al, o

ther

grou

ps th

at c

an s

tabi

lize

an a

-car

bani

on)

CN

H

Sub

stitu

tion

of e

nola

tea

hyd

roge

n by

H, X

, or

R

O

R

H

EA

Dep

roto

natio

n–pr

oton

atio

n(m

ay le

ad to

rac

emiz

atio

nor

epi

mer

izat

ion)

O

R

X

Hal

ogen

atio

n

R´

O

R

R´

AH

Alk

ylat

ion

O

R

E

+

+ st

ereo

isom

er (

if a

car

bon

is, a

nd/o

r if

E c

onta

ins,

a s

tere

ogen

ic c

ente

r)

a

See Special Topic C in WileyPLUS



19.9 Summary of Important Reactions 897

19.9 Summary of Important Reactions

1. Claisen Condensation (Section 19.2):

2. Crossed Claisen Condensation (Section 19.2B):

3. Aldol Reaction (Section 19.4)General Reaction

Specific Example

OH–

H2O

–H2O2 RH

O

H

O

R

OH

R

RH

O

R

(1) C6H5CO2Et/NaOEt

Et/NaOEt

Et/NaOEt

Et/NaOEt

(2) H3O!

H3O!

H3O!

H3O!

(1) EtOCO(2)

O

(1) HCO2

(2)

(1) EtO2CCO2

(2)

O

R

OEt

O

OEt

OR

R

O OEt

OEt

O

ROEt

O

O H

ROEt

O

OO

OEt

(1) NaOEt

(2) H3O!

OEt

O

R2 R

O

R

OEt

O

±OH–

10°C–H2O

H

O

H

O

H

OOH

H

O



898 Chapter 19 Condensation and Conjugate Addition Reactions of Carbonyl Compounds

4. Directed Aldol Reactions via Lithium Enolates (Section 19.5B)General Reaction

Specific Example

5. Conjugate Addition (Section 19.7)General Example

Specific Example

Specific Example (Michael Addition)

6. Mannich Reaction (Section 19.8):

R

O

H H

O

H NR!

R"R

O

NR!

R"

! !

O

C6H5 C6H5

OC6H5 C6H5

OO

, HO–

MeOH

C6H5 C6H5

O

C6H5

H

CN

C6H5

OCN–

EtOH, HOAc

R¿

R–

R

O

R¿ R

OR–

HNu

(1) Nu – (or Nu¬H)

(2) H ¬ A

$

Nu–

Nu¬H=1º or 2º amines; an enamine=CN–; an enolate (Michael addition); R‡MgBr

LDA

THF, –78°C

O O–Li+ (1)

(2) NH4Cl

H

O

OH O

LDA

THF, –78°C(formation ofthe kinetic enolate)

RH(R¿)

O (1)

(2) NH4Cl

R‡R–

O

RH(R¿)

O–Li+R

OHR–R‡

H(R¿)

O




2. Steroids are an extremely important class of natural and pharmaceutical compounds. Synthetic efforts directed towardsteroids have been underway for many years and continue to be an area of important research. The synthesis ofcholesterol by R. B. Woodward (Harvard University, recipient of the Nobel Prize in Chemistry for 1965) and co-workers represents a paramount accomplishment in steroid synthesis, and it is rich with examples of carbonyl chem-istry and other reactions we have studied. Selected reactions from Woodward’s cholesterol synthesis and thequestions for this Learning Group Problem are shown in the WileyPlus materials for this chapter. Access thosematerials online to complete this problem.

CholesterolHO

H3

10A

9

C

B

13

20

17

14D

H

H

Me

8

H

Summary of Mechanisms

Enolate Reactions with Carbonyl Electrophiles

O–

O

Michael (conjugate) addition

Acyl substitution (addition–elimination), e.g., Claisen condensation when LG=OR

R¿ R‡

O

R¿R¿R–

R–

OR–

RR¿

R–

R‡

O O

R*

* *R¿

R–

R‡

* may be chirality centers

O–

R

O

R¿ LG

A –

(elimination ifa hydrogen

present)(E ) and (Z )

O

R R¿

R–

R¿

O

R

H

HO

R–

O–

R´

O

RLG

O O

R R´

Aldol reactions (addition and condensation)

O–

R

O–

R

O–

O

R

H A



910 Chapter 19 Condensation and Conjugate Addition Reactions of Carbonyl Compounds

HA

• E

nola

te fo

rmat

ion

• K

eto–

enol

taut

omer

ism

• H

alog

enat

ion

• A

lkyl

atio

n•

Acy

latio

n

Rea

ctio

ns o

f X a

s LG

, etc

.

(1)

R4M

gBr

or

R4L

i(2

) H

3O+

X2,

base

(1)

RO

–

(2)

R4X

(1)

RO

–

(2)

R3X

(3)

HO

–

(4)

H3O

+ , h

eat

(3)

H3O

+

(2)

(1)

LDA

The

n de

carb

oxyl

atio

nif

R2

= O

R

• C

lais

en c

onde

nsat

ion

• A

ldol

rea

ctio

ns•

Add

ition

of G

rigna

rd a

nd R

Li•

Mic

hael

add

ition

• C

onju

gate

add

ition

of H

CN

• C

onju

gate

add

ition

of a

min

es

O

R1

X

O

R1

OO

R1

R2

OO

R1

R2

R3

O

R1

R3

R4

CO

2!

R2

O

R2

LG

O

R2

R3

O

R1

O

Eno

late

s pr

ovid

e m

any

way

s to

func

tiona

lize

the a

-car

bon

of a

ca

rbon

yl c

ompo

und.

Mos

t im

port

antly

, eno

late

s pr

ovid

e w

ays

to fo

rm

new

car

bon–

carb

on b

onds

. Som

e of

thes

e sy

nthe

tic c

onne

ctio

ns a

re

show

n he

re. P

revi

ousl

y st

udie

d re

actio

ns o

f car

bony

l, al

coho

l, an

d al

kene

func

tiona

l gro

ups

(e.g

., re

duct

ion,

oxi

datio

n, a

dditi

on,

subs

titut

ion)

lead

to o

r fr

om s

ome

of th

ese

path

way

s.

Str

ong

base

(e.g

., LD

A)

Eno

late

res

onan

ce c

ontr

ibut

ors

R2

O

R

R3

NR

5R6

O

R1

R3 R

2

R3

O

R1

OH R

2

CN

O

R1

R3 R

2

+1,4

add

ition

Syn

thet

ic C

onne

ctio

ns

Som

e S

ynth

etic

Con

nect

ions

Invo

lvin

g E

nola

tes

R4

O

R1

OR

3 R2

R4

H

O(1

) LD

A,

(2)

H3O

+

HN

R5R

6H

CN

HA

or

wea

k A

–

–

–

(1)

LDA

(2)

R2X

(1)

LDA

(2)

O

RH

a

OH

R1

R1

R2

OH

R

R3

R4

See Special Topics D and E in WileyPLUS



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