Efficient total synthesis of dehydro-δ-viniferin through metal–halogen exchange cyclization

Abstract

Bioactive dehydro-δ-viniferin was synthesized through an efficient and practical eight-step route, achieving an overall yield of 27%. The synthesis process involves an intramolecular cyclization and dehalogenation via a metal–halogen exchange, producing 3-arylbenzofuran, with the di-iodinated α-aryloxyketone serving as the key intermediate. Long reaction times and the use of excess reagent i-PrMgCl·LiCl facilitate metal–halogen exchange cyclization and dehalogenation. This synthetic approach, scalable for the production of analogs, was successfully conducted for the first time in multigram quantities.