An Alkyne Metathesis Based Approach to the Synthesis of the Anti‐malarial Macrodiolide Samroiyotmycin A

We report the first total synthesis of samroiyotmycin A (1), a C(2)‐symmetric 20‐membered anti‐malarial macrodiolide isolated from Streptomyces sp. The convergent synthetic strategy orchestrates bisalkyne fragment‐assembly using an unprecedented Schöllkopf‐type condensation on a substituted β‐lactone and an ambitious late‐stage one‐pot alkyne cross metathesis–ring‐closing metathesis (ACM–RCAM) reaction. The demanding alkyne metathesis sequence is achieved using the latest generation of molybdenum alkylidynes endowed with a tripodal silanolate ligand framework. Subsequent conversion to the required E‐alkenes uses contemporary hydrometallation chemistry catalysed by tetrameric cluster [{Cp*RuCl}(4)]

Total Synthesis of Putative Xestocyclamine A

The first total synthesis of putative xestocyclamine A (-)-1 is reported, a compound taking center stage on the the pathway explaining the biosynthesis of a prominent family of polycyclic alkaloids (Baldwin-Whitehead pathway). The identity of the synthetic sample is unambiguous but the recorded spectral data deviate from those of xestocyclamine A reported in the literature