Dissecting a dyotropic rearrangement.

Herein we describe density functional theory calculations on nitroso acetal-to-aminal rearrangements reported by Denmark and co-workers. Our calculations indicate that various structural (ring strain, hyperconjugation, anomeric effects) and environmental (both specific and nonspecific solvation) factors greatly influence the ease of rearrangement. Our calculations also indicate that both concerted and stepwise mechanisms are energetically viable.