|
CHM 252 Organic Chemistry II
Spring 2001
Workshop #4
- All of the following reactions occur by analogous mechanisms. Derive a mechanism
for each of these reactions (split up group resonsibility here). Once you have shown all
of the mechanisms, try to come up with (by sharing your answers as a group) general
mechanistic categories. Make a table listing electrophiles and nucleophiles,
reaction by reaction, for the first mechanistic step and also for the second mechanistic
step.
- Complete the following reaction and give a reasonable mechanism. Clearly show ALL
intermediates and show the movement of electron pairs with curved arrows. Designate
the major and minor products of the reaction. Also, sketch a reaction energy diagram
that is consisent with your mechanism.
- When one of the stereoisomeric ethylene dicarboxylic acids (general strucutre shown
below) is reacted with Cl2/H2O, the corresponding chlorohydrin is
formed with the designated stereochemistry shown. Give the correct stereochemistry (E vs.
Z) for the starting ethylene dicarboxylic acid. Show the detailed mechanism for this
reaction using curved arrows to show the movement of electron pairs. Carefully explain how
your mechanism accounts for the stereochemistry of the reactant and product. (HINT: use
your model kit.)
- Compare/contrast the products (this is a regiochemistry problem) expected when the
substrate shown below reacts with each of the given reaction conditions. HINT: You’ll
want to consider the type of mechanism occurring in each case and how it determines
regiochemistry.
- Using the curved arrow formalism, suggest mechanisms for each of the following
reactions.
|
