Chemistry 336 Exam 3
Winter 1998 100 pts Name ___________________________________

Note: The last page of the exam is a list of organic starting materials, inorganic reagents and spectral tables to be used for the exam.

1. (24 pts) Draw the chemical structure(s) of the product(s) expected for the following reactions. Indicate stereochemistry when relevant.

2. (14 pts) Suggest a plausible mechanism for the following reaction using arrow formalism. Your mechanism must include each step and illustrate explicitly where electrons and atoms are participating in the reaction.

3. (12 pts) A student attempted to alkylate 3-methoxycyclohexanone and instead isolated a compound labeled here as product A (below). Had the student considered the mechanism, he/she should have realized that the alkylation would not work. Draw the structure of product A and provide a mechanistic explanation for its production under these conditions.

4. (12 pts) For each of the following chemical reactions, fill in the box with the reagent(s) needed to produce the illustrated transformation.

5. (15 pts) The alkylation of the tricyclo-[2.2.2]-octenone gives predominately the one isomer shown below:

(a) Briefly explain why the alkylation is predominately at position-2 and not position-7.

(b) Briefly explain the observed stereochemistry for this alkylation.

6. (14 pts) Propose a plausible synthesis for the molecule below. For starting materials you are to use only those organic molecules in the Toobox (last page of exam) and any inorganic reagents.

7. (12 pts) Each of the following molecules can be synthesized by a Robinson Annulation. For each molecule give the retrosynthetic analysis for both the intramolecular aldol and Michael reactions. You do not need to show the reagents needed to do the reaction. You also do not need to show the synthesis of the starting materials.