Toward the total synthesis of citreamicin η: Synthesis of the pentacyclic core and GAB-ring annelation model studies
作者:Shawn Blumberg、Stephen F. Martin
DOI:10.1016/j.tet.2018.04.049
日期:2018.9
di-tert-butylsilyl (DTBS) ethers to protect electron-rich benzyl alcohols toward ionization under acidic conditions. We also developed an improved protocol for selective o-bromination of phenols utilizing N-bromosuccinimide (NBS) and tetramethylguanidine (TMG) that promises to be generally useful. Finally, we developed a modular approach for the synthesis of isoquinolones and dihydro-5H-oxazolo[3,2-b]isoquinoline-2
多环黄酮抗生素citreamicamicinη的五环核的短时11步合成已经完成。尽管基本方法是由我们先前对多环蒽酮化学的探索启发而来的,但本报告对摩尔重排有一些新见解,并对我们的原始方法进行了一些改进,包括将芳基锂添加到方酸酯中,将乙炔铈铈添加到受阻酮中。利用PDA作为内部指示剂,以及使用环状二叔丁基甲硅烷基(DTBS)醚保护富含电子的苄醇在酸性条件下不被电离。我们还开发了用于选择性的改进的协议ø利用酚的-bromination N-有望普遍使用的溴代琥珀酰亚胺(NBS)和四甲基胍(TMG)。最后,我们开发了一种用于合成异喹诺酮和二氢-5H-恶唑并[3,2 - b ]异喹啉-2,5(3H)-二酮的模块化方法,该方法具有烷氧基羰基化,丙酮芳基化,酰胺基转移的新序列。
A novel α,β-unsaturated nitrone-aryne [3+2] cycloaddition and its application in the synthesis of the cortistatin core
作者:Mingji Dai、Zhang Wang、Samuel J. Danishefsky
DOI:10.1016/j.tetlet.2008.09.019
日期:2008.11
We describe here a novel alpha,beta-unsaturated nitrone-aryne [3+2] cycloaddition. The resulting benzoisoxazolines underwent N-O bond reduction-elimination-electrocyclization sequence to furnish a variety of polysubstituted 2H or 2-alkylated-1-benzo-pyrans. The application of this methodology was further demonstrated in the synthesis of the oxa[3.2.1]octene moiety of cortistatin A.
我们在这里描述了一种新型的 α、β-不饱和硝酮-芳烃 [3+2] 环加成反应。所得苯并异恶唑啉经历 NO 键还原-消除-电环化序列,以提供各种多取代的 2H 或 2-烷基化-1-苯并-吡喃。这种方法的应用在皮质抑素 A 的 oxa[3.2.1] 辛烯部分的合成中得到了进一步证明。
An Efficient Preparation of 6-Alkoxy-substituted Benzocyclobutenones
作者:Christopher J. Bungard、Jonathan C. Morris
DOI:10.1055/s-2001-12767
日期:——
A short, efficient route to 3-alkoxybenzynes has been developed, starting from readily available compounds. This has enabled rapid access to 6-alkoxybenzocyclobutenones, which are valuable synthetic intermediates.