Problem Set 2 –
Conjugated Systems
- 3-Buten-2-ol reacts with cold HBr
to give 15% 1-bromo-2-butene and 85% 3-bromo-1-butene. After heating, the
major product is 1-bromo-2-butene.
- Propose a mechanism to explain
the formation of the two products.
- Identify the main product
obtained in the reaction that is under thermodynamic control.
- Identify the main product
obtained in the reaction that is under kinetic control.
- Identify the diene and the
dienophile that you would use to synthesize the following compound:
- Draw the structure of the
following Diels-Alder reaction:
- Treatment of isoprene
(2-methyl-1,3-butadiene) with catalytic amounts of acid leads to a variety
of oligomeric products, one of which is limonene:
a. Devise a detailed mechanism for the
acid-catalyzed conversion of two molecules of isoprene into limonene.
b. Two molecules of isoprene may also be
converted into limonene by a completely different mechanism, which takes place
in the strict absence of catalysts of any kind.
Describe this mechanism.
c. What is the name of the reaction?