Diazonamide first total synthesis

Nicolaou KC, Chen D Y-K, Huang X, Ling T, Bella M, Snyder SA (2004) Chemistry and Biology of Diazonamide A First Total Synthesis and Confirmation of the True Structure. J Am Chem Soc 126 12888... 

Shortly after Harran s structure revision of diazonamide A (47), Nicolaou and coworkers reported the first total synthesis [39]. Retrosynthetically, assembly of fragments 63-67 could lead to diazonamide A through side-chain excision, chlorination, macrolactamization, aminal and oxazole formation, and bis-aryl ring realization (Scheme 10). 

Scheme 11. Final stages and completion of the first total synthesis of diazonamide A (1).

In an approach toward the synthesis of the marine natural product cytotoxin Diazonamide A, the arylation of a lactonic /3-diester 20 with a tyrosinyllead triacetate was realized and afforded 21 as a mixture of diastereomers in 85% overall yield from 3-iodotyrosine (Scheme 5).36 It later appeared that the first suggested structure of Diazonamide A37 was in fact erroneous38, a and that the organolead-based approach could not be used for the total synthesis of this natural product. 

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