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CHE 322
Exam 3
May 7, 2012
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Name
1. (10) Explain the difference between “hard” and “soft” nucleophiles. Give a structure of each kind that supports
your description.
2. Predict the major product (3 pt each)
NH trace H+
a.
Br
O
anhydrous
1)
b.
EtOOC
H2O
EtO-, one eq.
2)
COOEt Br
drip in
low conc in EtOH
e.
H+
O
1) EtO-
OEt
2)
EtO-, one eq. H+
H2O
Br
OEt (drip in)
O
1) LDA
g.
O
2)
3) NaBH
4
4) H O
2
O
Cl
h.
1) Et CuLi
2
O
2) H O
2
hot
dry
3. (8) Give the complete mechanism that shows why the reaction of butanal with a cyclic 2° amine followed by
heating with acid produces an enamine that is nucleophilic at butanal’s former α-carbon.
4. Synthesize from any needed inorganic or specialty compound plus the indicated carbon sources:
a. 2-heptanone from simple alcohols of 4 C or fewer. No strong base like LDA is available. (10 pt)
COOEt from toluene and simple alcohols of 4 C or fewer (6 pt)
b.
Ph
c.
O
from benzene (4 pt)
5. (4 each) What stable smaller compounds (that one could purchase) would you combine, and under what
conditions, to make the indicated large compound? In each case show the reaction that makes the C-C or C-O
bond that links the pieces. All three must be different kinds of reactions. [Caution: parts of some reaction
partners are missing in the given products due to replacement or subsequent reactions during workup.]
6. (4 each) Say whether and why each of the following transformations is likely to succeed or fail in giving a
decent yield of the indicated product.
a.
O
O
O
EtO-
O
COOEt
O
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c.
O
EtOOC
EtO(one eq.)
N
1)
H+, H2O
2)
hot
COOH
O
7. (8) Is alkylation of 1-aminobutane with 1-bromobutane using one equivalent of each to produce dibutylamine a
good plan? Explain, giving all important reasons.