Scheme 1: Substrate Scope a a Reactions were performed on 0.5-mmol scale unless otherwise specified. Analytical yields and TTN were determined by GC-FID. Yields for isolated and purified material are designated in parentheses. The er was determined by Chiral GC. For 0.5-mmol scale reactions, all numbers reported represent the average of two trials. For 10-mmol scale reaction, numbers reported represent one run.