Ch211 Alkynes Problem Set 1. Provide The Products For The

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

+