作者:D. B. Rubinov、I. L. Rubinova、F. A. Lakhvich
DOI:10.1134/s1070428011020199
日期:2011.2
Reactions of 2,2-dimethyl-5-(3-oxoalkanoyl)-1,3-dioxane-4,6-diones with alkoxyamines proceed regioselectively at the β′-keto group of the side acyl chain affording the corresponding tricarbonyl imines whose boiling in toluene leads to the formation of products of intramolecular cyclization, N-alkoxy-2,4-dioxopyridine-3-carboxylic acids. The decarboxylition of the obtained pyridine-3-carboxylic acids
2,2-二甲基-5-(3-氧代烷酰基)-1,3-二恶烷-4,6-二酮与烷氧基胺的反应在酰基侧链的β'-酮基上进行区域选择性反应,得到相应的三羰基亚胺,其沸腾甲苯中的N-烷氧基导致分子内环化产物N-烷氧基-2,4-二氧代吡啶-3-羧酸的形成。在160-165°C下,将所得的3-吡啶吡啶羧酸在亚甲基苯中脱羧,可制得N-烷氧基吡啶-2,4-二酮。从IR和NMR光谱出发,讨论了Meldrum酸的5-酰基衍生物系列和获得的N-烷氧基吡啶-2,4-二酮的酮-烯醇和亚胺-烯胺互变异构问题。