The first total synthesis of ratjadone was achieved using a highly convergent approach joining three subunits together with a Wittig olefination and a selective Heck reaction as the pivotal steps. Besides establishing a robust and reliable route for the synthesis of this orphan ligand, the configuration of unknown stereocenters could also be determined. This synthesis not only provides an additional access to a biologically important compound but also enables the synthesis of structural analogues for biological target identification.

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[structure: see text] The first enantioselective total synthesis of tonantzitlolone, a novel 15-membered macrocyclic diterpene, utilized a Julia olefination, a highly selective, potassium enolate-based anti-Felkin aldol reaction, and an E-selective ring-closing metathesis as key C-C bond-forming steps. The absolute configuration of tonantzitlolone is established.

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The coupling of three fragments by a Wittig olefination and a subsequent selective Heck reaction are the pivotal steps in the the first total synthesis of ratjadone (see picture), a cytotoxic as well as antibiotically effective polyketide. This synthesis enabled the elucidation of the absolute configuration of the natural product. In this way it should also be possible to synthesize structural analogues with which the various cellular processes mediated by ratjadone can be studied.