A highly efficient gold-catalyzed approach between N,Oacetals and ynamides for the construction of 6-(tert-butyldimethylsilyl)oxytetrahydropyrrolo[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).