CHEMISTRY 3302 June 4, 1998



1) Neither calculators nor notes of any kind are allowed while taking the exam. The periodic table is, of course, freely available.

2) Sign the first exam page at the top with your name (please also print your name to ensure legibility). To be considered for regrading, the exam must be taken in ink.

3) If a problem is giving you particular difficulty, go on with other questions and return to it as time allows. The questions are approximately in order of difficulty.

4) Concise explanations which expand upon your answers are encouraged. Partial credit will be liberally awarded if it is clear that you had the right idea, but simply made a small mistake at a later point in the answer. Don't get carried away, however, as this will waste your time.







I. Molecular Properties (25 points)

Circle the one choice that fits the described property.

Least reactive to nucleophilic substitution by MeO-

Strongest base

Best acceptor for Michael (1,4) addition

Highest boiling point

Strongest acid

II. Chemical Transformations (28 points)

Fill in the boxes with the appropriate educts, reagents, or products. A normal workup is assumed. Be sure to show stereochemistry if necessary to distinguish isomers.

III. Organic Logic and Analysis (20 points)

Consider the following transformation of a g-aminoester to a lactam:

a. Write a step-by-step mechanism for the formation of the lactam.

b. On the previous page, circle the most basic atom (i.e., the site that is most readily protonated by an acid) in the starting material and in the product. If it is a different atom in the product than in the starting material, explain why a change has occurred.

c. This reaction is, in fact, a reversible equilibrium. What drives this reaction to the right?

IV. Multistep Synthesis (27 points possible)

On the next page is a list of 8 reagents (feel free to tear it off). You will need 6 of these reagents to complete the total synthesis outlined below (2 are not used). Fill in the reagents by letter in the boxes over the reaction arrows. The structures of the starting material, final product, and one intermediate are provided, as is one set of reagents. Draw the correct structures for all other intermediates in the boxes provided. Certain spectral clues are listed under some of the structure boxes. A normal workup is assumed for all reactions.