Bioinspired Synthesis of Platensimycin from Natural -Kaurenoic Acids.

The biomimetic formal synthesis of the antibiotic platensimycin for the treatment of infection by multidrug-resistant bacteria was accomplished starting from either -kaurenoic acid or grandiflorenic acid, each of which is a natural compound available in multigram scale from its natural source. Apart from the natural origin of the selected precursors, the keys of the described approach are the long-distance functionalization of -kaurenoic acid at C11 and the efficient protocol for the A-ring degradation of the diterpene framework.