General, Regiodefined Access to α-Substituted Butenolides through Metal−Halogen Exchange of 3-Bromo-2-silyloxyfurans. Efficient Synthesis of an Anti-inflammatory Gorgonian Lipid
摘要:
A variety of alpha-substituted butenolides were efficiently prepared from 3-bromo-2-triisopropylsilyloxyfuran via lithium-bromine exchange and in situ quench with carbon or heteroatom electrophiles. The inherent flexibility of this methodology is illustrated by a short and efficient synthesis of an anti-inflammatory marine natural product.
Asymmetric Total Synthesis of Aglacins A, B, and E
作者:Mengmeng Xu、Min Hou、Haibing He、Shuanhu Gao
DOI:10.1002/anie.202105395
日期:2021.7.19
An asymmetric photoenolization/Diels–Alder (PEDA) reaction between electron-rich 2-methylbenzaldehydes and unsaturated γ-lactones was developed to directly construct the basic tricyclic core of aryltetralin lactone lignans. This methodology enabled the first asymmetrictotalsynthesis of aglacins A, B, and E and revision of the absolute configuration of these natural lignans. The strategy was also
开发了富电子2-甲基苯甲醛和不饱和γ-内酯之间的不对称光烯醇化/狄尔斯-阿尔德(PEDA)反应,以直接构建芳基四氢萘内酯木脂素的基本三环核心。这种方法实现了 aglacins A、B 和 E 的第一次不对称全合成,并修正了这些天然木脂素的绝对构型。该策略还用于通过四步和六步制备天然存在的芳基二氢萘型木脂素 (-)-7,8-二氢异正义素 B 和 (+)-linoxepin,以及 27 个含有 C8' 的天然产物样分子第四纪中心。我们相信合成的 aglacins 和小分子文库为进行天然产物鬼臼毒素家族的 SAR 研究提供了新的机会。
tetracyclic compound as follows: The vinyl ether and acetylenic moieties were reduced and the siloxy group was removed with a Barton–McCombie reaction. The construction of the six‐membered ether and the γ‐lactone provided the tetracyclic compound. Finally, a phenolic moiety was introduced by using a Mukaiyama aldol reaction to furnish polygalolide A.
from commercially available (+)-sclareolide, the first synthesis of zerumin B was achieved by a concise, highly efficient pathway featuring stereoselective addition of a new silyloxyfuryltitanium reagent to an aldehyde intermediate and silyloxyfuran oxyfunctionalization as key steps. The synthesis established the relative and absoluteconfiguration of zerumin B along with its identity with a purportedly
Synthesis of stable isotopically labelled 3-methylfuran-2(5<i>H</i>)-one and the corresponding strigolactones
作者:Yun Cheng、Wen-hui Ding、Qin Long、Min Zhao、Jun Yang、Xiao-qiang Li
DOI:10.1002/jlcr.3311
日期:2015.7
Conventional synthetic procedures of strigolactones (SLs) involve the independent synthesis of ring ABC and ring D, followed by a coupling of the two fragments. Here we prepared three kinds of stable, isotopically labelled D-ring analogues productively using a facile protocol. Then, a coupling of the D-rings to ring ABC produced three isotope-labelled SL derivatives. Moreover, (+)-D3-2′-epi-1A and (−)-ent-D3-2′-epi-1A with high enantiomeric purity were obtained via chiral resolution.