A HMPA-H 2 O mediated oxygenative carbocyclization of 2-alkynylphenyl-substituted p -quinone methides to indenones.

Herein, we report a transition-metal and base-free protocol to access a wide range of functionalized indenone derivatives through a HMPA-H 2 O-mediated oxygenative annulation of 2-alkynylphenyl-substituted p -quinone methides. This method worked effectively for most of the p -QMs investigated and the corresponding indenone derivatives were obtained in moderate to good yields. This methodology was further extended to the formal synthesis of one of the resveratrol based natural products, (±)-isopaucifloral F.