A Convergent and Stereocontrolled Cycloaddition Strategy toward Eudesmane Sesquiterpenoid: Total Synthesis of (±)-6β,14-Epoxyeudesm-4(15)-en-1β-ol

We present in this report the development of a convergent and highly stereocontrolled cycloaddition strategy toward the synthesis of C-1, C-6, and C-14 tris-oxygenated eudesmane sesquiterpenoids. This approach was demonstrated in the first total synthesis of (±)-6β,14-epoxyeudesm-4(15)-en-1β-ol (1), a structurally unique ethereal eudesmane sesquiterpenoid, via an effective Diels–Alder construction of a compact functionalized tricycle intermediate from readily available N-benzylfurfurylamine (2) and homoprenyl maleic anhydride (3) as the C5 and C10 building blocks, respectively.