Gold and brønsted acid catalyzed hydride shift onto allenes: Divergence in product selectivity

Abstract : A series of allenyl ethers can be transformed into various fused or spiro tetrahydrofurans and tetrahydropyrans following a hydride shift/cyclization sequence. A divergence in product selectivity, which depends on the nature of the catalyst used (Au(I) complex or Brønsted acid), was observed. © 2011 American Chemical Society.