Total Synthesis of (±)-Rubriflordilactone A

Key words

(±)-rubriflordilactone A - Schisandra triterpenoids - Fries–Finck rearrangement - Prins cyclization - photooxygenation - Mukaiyama hydration

Significance

Chen and co-workers present the total synthesis of (±)-rubriflordilactone A, a highly oxygenated polycyclic triterpenoid isolated from Schisandra plants, which exhibits anti-HIV activity. The natural product, with its central polysubstituted arene motif, is accessed via a rare ortho-quinone methide type [4+2]-cycloaddition.

Comment

Commercially available phenol A was elaborated into key butenolide H. Treatment of the latter with BF₃·OEt₂ initiated an intramolecular Prins cyclization, affording a seven-membered ring in J. Mukaiyama hydration triggered an oxa-Michael reaction, affording γ-lactone L that, after reduction, was reacted with furan M in a [4+2]-cycloaddition. Subsequently, photooxygenation and reduction furnished (±)-rubriflordilactone A.

Publication History

Article published online:
14 May 2024