Gold-Catalyzed Addition–<i>N</i>‑Boc Cleavage–Cyclization of <i>N</i>,<i>O</i>‑Acetal with Ynamides for Construction of 6‑(<i>tert</i>-Butyldimethylsilyl)oxy-tetrahydropyrrolo[1,2‑<i>c</i>][1,3]oxazin-1-ones

A highly efficient gold-catalyzed approach between N,O-acetals and ynamides for the construction of 6-(tert-butyldimethylsilyl)­oxy-tetrahydropyrrolo­[1,2-c]­[1,3]­oxazin-1-ones was developed. This reaction tolerated a wide range of substituted N,O-acetals and TsN-substituted ynamides, leading to novel heterocycles in moderate to good yields and with excellent diastereoselectivities (dr > 99:1).