CH211 ALKYNES Problem Set
1. Provide the products for the following reactions. Provide the mechansims for the reactions that are starred.
Br
Br2
a) *
1eq. HBr
h) *
Br
Br
Br Br
1) NaNH2
2) CH3Cl
i) *
HgSO4, H2SO4
3) H2O
b)
H2O
O
1) NaNH2
j)
c)
Ph
2) PhCH2Br
3) H2O
H2/ Pd-C
Br Br
k)
H2/ Lindlar's
Me
Br2
Et
Br Br
d)
catalyst
l)
Me
Li / NH3
Et
O
1) BH3
Li / NH3
e)
m)
H
2) H2O2, H2O,
KOH
H2/ Lindlar
f)
Br
1) 2 eq. NaNH2
n)
2) H2O
Br
HBr
g)
o)
Br Br
1) Br2
*
2) 2eq. NaNH2
3) H2O
Br Br
2. Provide synthesis for the following molecules from the given starting materials. Work backwards first! Do the retrosynthetic analysis, then
do the forward steps. Other routes are certainly possible.
d)
O
Br
Br
a)
H
1) NaNH2
2) 1-bromobutane
Br
H
Br2
CCl4
Li/ NH3
1) NaNH2
2) 1-bromoethane
Br +
b)
e)
Li / NH3
OH
1) NaNH2
2) 1-bromobutane
Br
1) NaNH2
2) 1-bromopropane
1) BH3
2) H2O2, H2O
NaOH
Br
Li/ NH3
1) NaNH2
2) 1-bromopropane
Br
+
f)
c)
HO H
O
1) Hg(OAc)2, H2O
2) NaBH4
Br
Li/ NH3
mCPBA
1) NaNH2
2) 1-bromobutane
Li/ NH3
1) NaNH2
2) 1-bromopropane
Br
+