Trifunctional reagents for substrate-protein conjugation: Application to pyrrolizidine alkaloid analogues

Article abstract of DOI:10.1016/S0040-4020(01)92230-6

We report the syntheses of two pyrrolizidine alkaloid (PA) analogues (1 and 2) which exploit the novel substrate-protein coupling reagents 4 and 5. Analogues 1 and 2 incorporate the targeted PA substructural unit (i.e., a macrocyclic diester of retronecine), possess a handle for protein conjugation, and potentially maintain the conformational integrity of macrocyclic PAs.