Asymmetric Total Synthesis of Shagenes A and B

Abstract

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.

Catalytic Asymmetric Syntheses of Alkylidenecyclopropanes from Allenoates with Donor‐Acceptor and Diacceptor Diazo Reagents

“…Enantioenriched alkylidenecyclopropanes (ACPs) are attractive structural motifs due to their high potential as synthetic key building blocks in a vast array of transformations [1] . Many syntheses of biologically important compounds were developed using ACPs as a strategic intermediate, such as DCG‐IV, [2] Shagenes A and B [3] or the 3‐azabicyclo[3,1,0]hexane scaffold. The latter constitutes the main structure of a large number of bioactive compounds, which exhibit an activity toward a broad range of Gram‐positive pathogens [4] .…”

Total syntheses of strained polycyclic terpenes

“…These interesting targets were synthesised by Tsukano, Takemoto, and co-workers in 2021 ( Scheme 1 ). 3 One particular challenge in this polycyclic terpenoid involving the cyclopropane unit was the presence of a vinyl substituent, which potentially could lead to instability during chemical transformations. Three all-carbon rings were forged in only two chemical steps, showcasing fast and controlled construction of molecular complexity.…”

“…Total synthesis of terpenoids is a highly dynamic field with dozens of targets both classical and newly isolated being synthesised every year. In order to put the small ring containing terpenoids in a broader context, Chart 1 summarises a number of polycyclic terpenes 2–36 prepared over the last 5 years, highlighting key reactions, utilised to form the corresponding ring systems. This chart is intended to give a reader an overview of modern approaches to construction of polycyclic carbon architectures in modern synthetic chemistry.…”

Total Syntheses of Conhydrines via Ruthenium-Catalyzed Ring-Closing Metathesis (RCM) Reactions

“…In a recent example, Takemoto, Tsukano and co-workers completed the first asymmetric total synthesis of shagenes A and B by using RCM reaction of an enamide and Ir-catalyzed double-bond isomerization of an alkylidenecyclopropane as the key steps. 28…”