Synthesis of 1,3‐cis‐Fused Tricyclic System through Regio‐ and Stereoselective Epoxidation and Ring‐Rearrangement Metathesis: Access To Basic Core of Presilphiperfolanols

Abstract

AbstractHere, we report a new synthetic approach to a highly strained 1,3‐fused cis‐cis‐cis‐5/5/6 tricyclic system that appeared among the presilphiperfolanol analogues. The cis‐fusion of six‐membered ring to a diquinane moiety is accomplished by substrate‐controlled regio‐ and stereoselective epoxidation, and ring‐rearrangement metathesis (RRM) sequence. In this regard, both early‐, and late‐stage epoxidation and RRM reactions were studied. The target compound, cis‐cis‐cis‐5/5/6 tricyclic ketone with an α,β‐oxirane ring can serve as a key building block to produce various presilphiperfolanol analogues. The cis‐cis‐cis‐5/5/6‐tricyclic‐α,β‐epoxyketone can also act as masked enone and therefore useful for various chemical transformations in organic synthesis. The short synthetic sequence disclosed here may be useful to design various biologically important molecules. The newly reported molecules are well‐characterized by NMR, HRMS, and IR spectral data.