[(5,6-Dihydro-4 H-1,2-oxazin-3-yl)methyl]malonates undergo a cascade transformation into substituted methyl 7-oxo-1-oxa-6-azaspiro[4.4]nonane-8-carboxylates under catalytic hydrogenation conditions over Raney nickel. A mechanistic scheme involving initial N-O bond cleavage with the formation of imines as key intermediates is suggested.
[(5,6-Dihydro-4 H-1,2-oxazin-3-yl)methyl]
丙二酸酯经过级联转化为取代的 7-oxo-1-oxa-6-azaspiro[4.4]nonane-8-carboxylates在雷尼
镍催化加氢条件下。提出了一种涉及初始 NO 键断裂并形成
亚胺作为关键中间体的机制方案。