(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。
The first total synthesis and revision of absolute stereochemistry of natural cytotoxic lactone cleistanolate
作者:Jelena Kesić、Ivana Kovačević、Mirjana Popsavin、Goran Benedeković、Marko V. Rodić、Vesna Kojić、Velimir Popsavin
DOI:10.1016/j.bioorg.2022.106073
日期:2022.11
applicable to d-ribose and d-xylose enabled the synthesis of cleistanolate putative structure, its five stereoisomers, and led to revision and confirmation of absolute stereochemistry of the natural product. Key steps of the synthesis included zinc-mediated THF ring-opening and stereoselective dihydroxylation under the Upjohn conditions. The first total synthesis of cleistanolate was completed in eight steps
Reaction of D-glucose, D-galactose or D-xylose with carbomethoxymethylenetriphenylarsonium ylide in refluxing dioxane leads to corresponding 3,6-anhydro-2-deoxy-octono or heptano-1,4-lactones in good yield (C) 1997 Published by Elsevier Science Ltd.
Synthesis and epimerisation studies on carbohydrate derived bicyclic tetronate esters: The synthesis of furanofurans related to the cytotoxic metabolite goniofufurone
作者:Cristiano Cagnolini、Marina Ferri、Peter R. Jones、Patrick J. Murphy、Barry Ayres、Brian Cox
DOI:10.1016/s0040-4020(97)00164-6
日期:1997.3
The synthesis of the D-xylo- 12, D-lyxo- 13, D-ribo- 14 and D-arabino-furanofurans 15 was accomplished from the readily available butyrolactones 4 and 5 via a non-classical Wittig cyclisation/hydrogenation sequence; these compounds are analogues of the cytotoxic natural product goniofufurone. (C) 1997 Elsevier Science Ltd.
Synthesis of anti-proliferative [3.3.0]furofuranone derivatives by lactonization and functionalization of C-glycosyl compounds
advantage of the stereodiversity afforded by carbohydrate derivatives to prepare several compounds structurally similar to goniofufurone and crassalactones which are natural cytotoxic agents. We designed and synthesized several stereoisomers of these natural compounds via lactonization of C-glycosylcompounds bearing an hydroxyl on position 4 and a methyl ester on the pseudo-anomeric positionThe reactivity