Amino Acid Derived Heterocycles: Lewis Acid Catalyzed and Radical Cyclizations from Peptide Acetals
作者:Matthew H. Todd、Chudi Ndubaku、Paul A. Bartlett
DOI:10.1021/jo010990m
日期:2002.6.1
of peptide acetals via nucleophilic attack of a phenyl group on an endocyclic acyliminium ion 4 was explored as a route to novel amino acid derived heterocycles and peptidomimetic scaffolds. In the presence of protic acid, bridged structures such as 6 are formed readily from phenylalanine derivatives, but the fused-ring analogues 5 could not be obtained in good yield. In contrast, radical cyclization