Deoligomerization: A new route to Lactams from unsaturated amides via radical oligomerization

Triethylborane-initiated atom transfer radical oligomerization of N-allyl or N-(3-butenyl)iodoacetamides followed by treatment with hydrochloric acid and subsequent neutralization with K2CO3 led to the formation of the corresponding 5-hydroxyl-substituted delta-lactams or caprolactams, respectively. This oligomerization-deoligomerization sequence serves as an alternative to the corresponding intramolecular cyclization reactions.