Comprehensive Reinvestigation of The Reaction of D-Aldoses With Meldrum'S Acid Yielding Mainly Chain Extended 3,6-Anhydro-2-Deoxy-Aldono-1,4-Lactones
作者:Peter Köll、Angelika Wernicke、József Kovács、Arne Lützen
DOI:10.1080/07328300008544132
日期:2000.1.1
(butenolides) which in some cases could be isolated as by-products. Epimerisation at C-2 of the parent aldose occurred at least partially in most reactions. The products and their acetylated derivatives were characterized by 1H and 13C NMR spectroscopy. A proposed mechanism of this reaction is supported by additional experimental evidence.
摘要在碱性条件下,所有非对映异构的醛基-D-戊糖和-D-己糖都与Meldrum的酸(2,2-二甲基-1,3-二恶烷-4,6-二酮)反应。最初由JA Galbis Perez等人报道的一种协议已被应用和优化。在1990年,在每种情况下,都发生了端基异构羟基被羧基-亚甲基正式取代,从而使母体醛糖的碳链延长了一个C2片段。产品主要是3,6-脱水-2-脱氧-醛基-1,4-内酯,其中内酯环被环化成呋喃类化合物。但是,D-甘露糖和D-lyxose也产生了吡喃类化合物3,7-脱水-1,4-内酯。中间体是不饱和的开链1,4-内酯(丁烯内酯),在某些情况下可以分离为副产物。在大多数反应中,母体醛糖在C-2处的差向异构化至少部分发生。产物及其乙酰化衍生物通过1 H和13 C NMR光谱表征。该反应的拟议机制得到了其他实验证据的支持。