Total Synthesis of Blennolide Mycotoxins: Design, Synthetic Routes and Completion
作者:Anne C. Meister、Arantxa Encinas、Hülya Sahin、Emilie M. C. Singer、Carl F. Nising、Martin Nieger、Stefan Bräse
DOI:10.1002/ejoc.201402083
日期:2014.8
Mycotoxins of the tetrahydroxanthone class of natural products possess a large number of interesting biological properties. In this full paper, we present our synthetic strategy to some members of this class of compounds, namely the blennolides A and C. We disclose the scope and limitations of the functionalization of various xanthones derived from a domino oxa-Michael-aldol condensation and pursue
四氢氧杂蒽酮类天然产物的霉菌毒素具有许多有趣的生物学特性。在这篇完整的论文中,我们向此类化合物的一些成员介绍了我们的合成策略,即 blennolides A 和 C。我们公开了衍生自多米诺氧杂-迈克尔-羟醛缩合的各种氧杂蒽酮官能化的范围和局限性,并追求这些氧杂蒽酮的二聚化。此外,还获得了 blennolide C 的第一个晶体结构。
Asymmetric synthesis of chromanone lactones <i>via</i> vinylogous conjugate addition of butenolide to 2-ester chromones
The scope of Michael acceptors includes a variety of substituted chromones at different positions, and the desired chromanone lactones upon reduction are afforded in good yield and diastereoselectivity, and excellent enantioselectivity (up to 99% ee). The strategy could be used in the concise synthesis of blennolide C and gonytolide A, C and G.
手性色满酮内酯是一类具有重要生物活性的天然产物。我们报道了丁烯内酯与2-酯取代的色酮的直接非对映和对映选择性插烯共轭加成。在低至 1 mol% 的手性N , N'-二氧化物/Sc III络合物、3 Å MS 和催化量的六氟异丙醇 (HFIP) 的存在下,转化顺利进行。迈克尔受体的范围包括各种不同位置取代的色酮,还原后得到所需的色酮内酯,具有良好的产率和非对映选择性,以及优异的对映选择性(高达99% ee)。该策略可用于blennolide C和gonytolide A、C和G的简捷合成。
Vinylogous Addition of Siloxyfurans to Benzopyryliums: A Concise Approach to the Tetrahydroxanthone Natural Products
作者:Tian Qin、Richard P. Johnson、John A. Porco
DOI:10.1021/ja110698n
日期:2011.2.16
A concise approach to the tetrahydroxanthone natural products employing vinylogous addition of siloxyfurans to benzopyryliums and a late-stage Dieckmann cyclization has been developed. With this methodology, chiral, racemic forms of the natural products blennolides B and blennolide C have been synthesized in a maximum of four steps from a 5-hydroxychromone substrate. The regio- and diastereoselectivity of the vinylogous additions was probed using computational studies, which suggested the involvement of Diets Alder-like transition states.
Modular Syntheses of Diversonol-Type Tetrahydroxanthone Mycotoxins: Blennolide C (epi-Hemirugulotrosin A) and Analogues
作者:Emilie M. C. Gérard、Stefan Bräse
DOI:10.1002/chem.200801507
日期:2008.9.19
Total synthesis of (+)-blennolide C and (+)-gonytolide C via spirochromanone
We report the asymmetric total synthesis of (+)-blennolide C and (+)-gonytolide C isolated from endophytic fungi. The synthesis involved construction of a spirochromanone with a chiral quaternary carbon by the aldolreaction of o-hydroxyacetophenones and optically active α-oxygenated cyclohexenone, followed by cyclization under acidic conditions. Oxidative cleavage of the alkene moiety of the spirochromanone