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406 Chapter 11
Copyright © 2017 Pearson Education, Inc.
Bombykol can also be prepared using a Heck reaction.
OH
H
2
Lindlar
catalyst
OH
OH
PdL
2
(CH
3
CH
2
)
3
N
Br
45.
a.
2-butene and 3-hexene
b.
Two symmetrical alkenes. The only alkenes that will be synthesized other than the target alkene are the
reactant alkenes.
46.
+
Br
CH
2
(CH )
CuLi
2
O
O
HO
−
+
L Pd
2
O
Br
O
B
O
O
+ CH
2
2
N CH
2
3
(CH )
3
CH
O
Br
O
L Pd
2
47.
There are three possibilities:
A
,
B
, and
C
. Only the bromine bonded to the benzylic carbon can be replaced
by hydroxide ion via a nucleophilic substitution reaction. Both bromines in each compound can react with
magnesium to form a Grignard reagent. When the Grignard reagents are treated with acid, a H replaces
each of the bromines, so all three compounds form toluene.
or
or
CH
2
Br
Br
A
B
C
CH
2
Br
Br
CH
2
Br
Br
Compound
A
, for example, reacts as follows:
CH
2
Br
Br
CH
2
OH
Br
CH
2
Br
Br
CH
2
MgBr
MgBr
CH
3
HO
−
Mg
Et
2
O
HCl