Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10. 1002/anie.202109786.Scheme 1. Retrosynthesis of shagenes A and B. Angewandte Chemie CommunicationsScheme 3. Stereoselectivity of diastereoselective double-bond isomerization and relative thermodynamic stabilities of intermediates calculated by Spartan 18 at the wB97X-D/6-31G* level of theory.

We report the first total synthesis of shagenes A and B, which are tricyclic terpenoids containing a cis‐substituted cyclopropane, via ring‐closing metathesis of an enamide and Ir‐catalyzed double‐bond isomerization of an alkylidenecyclopropane. Chemo‐ and diastereoselectivity in the distorted cis‐substituted structures were controlled by the alkylidenecyclopropane reactivity and using the ketone functionality as a remote directing group for the Ir catalyst, respectively. The total synthesis suggested the absolute configuration of shagenes.

No abstract

Naturstoffsynthese In der Zuschrift auf S. 23290 präsentieren Chihiro Tsukano, Yoshiji Takemoto et al. die asymmetrische Totalsynthese von Shagen A und B.