Photolactamization: A novel synthetic entry into large ring-sized lactams

Article abstract of DOI:10.1016/0040-4039(92)88118-O

Diene ketenes smoothly accessible by photochemical ring cleavage of o-quinol acetates, in the presence of primary or secondary amines afford the corresponding amides. In an intramolecular version of this reaction macrocyclic lactams of type A are produced, if aminoalkylated o-quinol acetates of type C are used as photoreactants. These photoreactants are available on acid mediated removal of the Boc-protecting group from Wessely acetoxylation products of type D, easily formed via compounds of type E from aminoalkylated phenols of type F.