Horner–Wadsworth–Emmons reaction and acetal formation. The meso-syn-2,7-dimethyloxepane derivative was synthesized via photoinduced electrocyclization of a conjugated exo-diene under flow conditions, giving a cyclobutene derivative, followed by ring expansion via oxidative cleavage and diastereoselective reduction of a β-hydroxy ketone.
加勒比雪卡毒素 C-CTX-1 的 MN 环是由对应于 M 环的内消旋顺式-2,7-二甲基氧杂环庚烷衍生物通过与樟脑衍生物形成缩醛的去对称作用合成的,然后通过 Horner 构建 N 环–Wadsworth-Emmons 反应和缩醛形成。通过在流动条件下共轭外型二烯的光诱导电环化合成内消旋-顺式-2,7-二甲基氧杂环庚烷衍生物,得到环丁烯衍生物,然后通过氧化裂解和β-羟基酮的非对映选择性还原进行扩环。
Oxidative spirocyclisation routes towards the sawaranospirolides. Synthesis of ent-sawaranospirolides C and D
作者:Jeremy Robertson、Praful T. Chovatia、Thomas G. Fowler、Jonathan M. Withey、Daniel J. Woollaston
DOI:10.1039/b918091e
日期:——
Two routes are described for the synthesis of the sawaranospirolides, stereoisomeric spirolactone ascorbigenins isolated from Chamaecyparis pisifera. Trapping of the keto enal formed by oxidation of a functionalised 2-(4-hydroxybutyl)furan affords a potential butenolide spiroacetal precursor to sawaranospirolides A and C. Alternatively, epoxidation of protected 3-(dihydropyran-2-yl)-3-arylpropanoic
Synthesis of the southern furan segment of furanocembranoids
作者:Chada Raji Reddy、Siddique Z. Mohammed、Krishna Gaddam、Y. Lakshmi Prapurna
DOI:10.1080/00397911.2019.1587780
日期:2019.5.3
Abstract A convergent synthesis of the southern furan segment of novel furanocembranoids from Croton oblongifolius has been accomplished involving silver-catalyzed cyclization of alkynyl diol as the key step towards 2, 5-disubstituted furan ring formation. Graphical Abstract