Exam G8348 Advanced Organic Chemistry II:
Modern Molecular Photochemistry

Monday, December 13, 1999

Instructions: This is a one hour, closed book examination.
All material to be graded must be placed in a blue book with your name on the front cover.

1. (10 Points each question). Suggest a mechanism for the following photochemical reaction. Use only primary photochemical processes that are in the paradigms discussed in class, the text or problem sessions or explain your use of a novel paradigm.

2. (10 Points) Consider the following observations. Irradiation of cis-1,2-dicyanoethylene (cis-DCE) in acetone yields products (eq. 1 and eq. 2) which depend on concentration of cis-DCE. The oxetane (eq. 1) is favored by high concentration of cis-DCE and formation of the trans isomer (eq. 2) is favored by low concentration of cis-DCE. Suggest a mechanism which explains these observations.

3. (10 Points) Suggest a major product expected from the following reaction. Indicate your reasoning for full credit.