An Efficient Isoprenylation of Xanthones at the C1 Position by Utilizing Anion-Accelerated Aromatic Oxy-Cope Rearrangement

Abstract

An effective method for the installation of isoprenyl moiety at the C1 position of xanthone has been developed. Addition of isoprenyl Grignard reagent to 1-fluoroxanthone derivatives proceeded γ-selectively, and the obtained tertiary alcohols underwent aromatic oxy-Cope rearrangement and subsequent elimination of fluoride anion under mild conditions to give 1-isoprenylxanthones in high yields.