406954-62-9Relevant academic research and scientific papers
Amino acid derived heterocycles: Lewis acid catalyzed and radical cyclizations from peptide acetals
Todd, Matthew H.,Ndubaku, Chudi,Bartlett, Paul A.
, p. 3985 - 3988 (2007/10/03)
Bicyclization 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 of the bromophenyl dihydropyrazinone 7 provides an effective alternative for the synthesis of 5 (n = 0, 1, 2). Additional versatility in this process was demonstrated by efficient synthesis of a different fused ring system, represented by the antihelmintic praziquantel, 8.
