Total synthesis of elansolids B1 and B2.

The elansolids A1-A3, B1, and B2 are secondary metabolites formed by the gliding bacterium . They show antibacterial activity against Gram-positive bacteria. A second generation total synthesis of the antibiotic elansolid B1 () and the first synthesis of elansolid B2 () are reported. In contrast to previous work, the (-triene at C10-C15 was assembled by using an optimized C-C cross-coupling sequence with a Suzuki cross-coupling reaction as key step.