作者:Nils C. Eichenauer、Anja C. M. Nordschild、Martina Bischop、Dominik Schumacher、Marcel K. W. Mackwitz、Roxanne Tschersich、Thorsten Wilhelm、Jörg Pietruszka
DOI:10.1002/ejoc.201500700
日期:2015.9
The totalsynthesis of solandelactones A and B is presented. The eastern cyclopropyl moiety was prepared following an exceptionally short chemoenzymatic approach whereas enantioselective synthesis of the western side-chain relied on the application of diastereomerically pure allyl boronates. The natural products solandelactones A and B were isolated in good overall yields following convergence of each
介绍了茄内酯 A 和 B 的全合成。东部环丙基部分是按照非常短的化学酶促方法制备的,而西部侧链的对映选择性合成依赖于非对映异构纯硼酸烯丙酯的应用。通过应用 Nozaki-Hiyama-Kishi 反应将每个东西元素收敛后,天然产物茄内酯 A 和 B 以良好的总产率分离。
Total Synthesis of Solandelactones E and F, Homoeicosanoids from the Hydroid <i>Solanderia </i><i>secunda</i>
作者:James D. White、William H. C. Martin、Christopher Lincoln、Jongtae Yang
DOI:10.1021/ol701564x
日期:2007.8.1
Asymmetric total syntheses of solandelactones E and F confirmed that hydroxyl configuration at C11 in these oxylipins had been misassigned and that the stereochemistry at this center should be reversed. Key steps in the synthesis involved a Nagao asymmetric acetate aldol reaction, a directed Simmons-Smith cyclopropanation, a Holmes-Claisen rearrangement to establish the unsaturated octalactone, and
Total Synthesis of Solandelactones A, B, E, and F Exploiting a Tandem Petasis−Claisen Lactonization Strategy
作者:James D. White、Christopher M. Lincoln、Jongtae Yang、William H. C. Martin、David B. Chan
DOI:10.1021/jo800335g
日期:2008.6.1
Solandelactones A, B, E, and F were synthesized using Nozaki-Hiyania-Kishi coupling of iododiene 13 with aldehydes 14 and 99 obtained by oxidation of alcohols 92 and 94. Key steps in the synthesis of 92 and 94 were (i) a Nagao asymmetric acetate aldol reaction of aldehyde 77 with thionothiazolidine 78 to set in place an alcohol that becomes the (7S) lactone center of solandelactones, (ii) a Simmons-Smith cyclopropanation of 80 directed by this alcohol, and (iii) Petasis methylenation of cyclic carbonate 90 in tandem with a Claisen rearrangement that generates the octenalactone portion of solandelactones. Synthesis of solandelactones A, B, E, and F confirmed their gross structure and absolute configuration at C7, 8, 10, and 14 but showed that alcohol configuration at C11 must be reversed in pairs, A/B and E/F, from the previous assignment made to these hydroid metabolites. Thus, solandelactones A and B are correctly represented by 2 and 1, respectively, whereas solandelactones E and F are 6 and 5. A biogenesis of solandelactones is proposed for these C(22) oxylipins that parallels a hypothesis put forward previously to explain the origin of C(20) cyclopropane-containing algal products.