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[摘要]:Starting from pentanediol various oct-6-yne-1,5-diols were prepared. In the presence of catalytic amounts of an Au(I) or Pt(II) catalyst transformation to cis-2,6-tetrahydropyrans was observed. It is assumed that this novel domino sequence proceeds via an initial Meyer-Schuster rearrangement of the propargylic alcohol yielding a hydroxyenone that undergoes an intramolecular oxa-Michael addition through a chairlike transition state to the tetrahydropyran system. |
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