Total Synthesis of Lajollamycin B.

The first total synthesis of lajollamycin B, a structurally novel nitro-tetraene spiro-β-lactone/γ-lactone antibiotic, is described. The convergent synthesis involves the construction of the C8'-C11' nitrodienylstannane and its coupling with the segment prepared from the C1'-C7' ω-iodoheptadienoic acid and the right-hand heterocyclic fragment, which has been utilized for our previous syntheses of oxazolomycin A. The revision of the geometry of the terminal Δ10', 11' -double bond from E to Z is also described for the structure of natural lajollamycin B.