Discussion Section 10: Dienes

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Discussion Section 10: Dienes
1. Give the product(s) of the following reactions. Draw an arrow-pushing mechanism and explain what
conditions will favor each product, if there is more than one possible product.
2. Tell which of the following reactions has the greater or greatest value of the specified property. Clearly
explain the basis of your choice.
3. Predict the products or provide the missing reactants for the following reactions. Be sure to include
stereochemistry where appropriate.
CO2Me
Δ
+
CO2Me
O
Δ
+
O
Δ
+
Me
CO2Me
COOH
Δ
+
Me
4. It has been reported (Cooley and Williams, J. Chem. Ed. 1997, 74, 582-585) that the reaction of furan
with N-phenylmaleimide (A) gives a mixture of the adducts exo-B and endo-B. At a shorter reaction time
and lower temperature, endo-B is the predominant product. At longer reaction times and higher
temperatures, exo-B is the major product. Account for the variation in product ratios.
Conditions
7 days @ 0°C
20 days @ 25°C
A
14%
9%
exo-B
36%
68%
endo-B
49%
23%
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