Hg(OTf)2-catalyzed cyclization of an alkynyl alcohol on a tetra­hydropyran template gives the bispyranyl ketone arising from dehydrative cyclization and alkyne hydration, rather than the targeted fused pyran-oxepane product. The combination of stoichiometric Hg(OTf)2 and triethylsilane gives reductive cyclization, but affords the fused pyran-oxocane corresponding to an 8-endo-mode oxacyclization process.

中文翻译：

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汞促进的炔二醇氧杂环化的区域选择性

Hg(OTf)2 催化的炔醇在四氢吡喃模板上的环化产生了由脱水环化和炔水合产生的双吡喃酮，而不是目标稠合吡喃氧杂环庚烷产物。化学计量的 Hg(OTf)2 和三乙基硅烷的组合产生还原性环化，但提供对应于 8-endo-mode oxacyclization 过程的稠合吡喃-氧杂环己烷。