4‐pentadienale 3a–f werden aus den 3‐Phenyl‐propenal‐diethylacetalen la–f und Ethylvinylether dargestellt und ihre Oxime 4a–f in die (E)‐ und (Z)‐Isomere getrennt. Beim Einsatz der α‐verzweigten 5‐Phenyl‐2,4‐pentadienale 5a–d, die durch Aldolkondensation gewonnen werden, sind die einheitlichen (E)‐Oxime 6a–d zu erhalten.
Multicomponent Domino Synthesis of Cyclopenta[<i>b</i>]furan-2-ones
作者:Martín J. Riveira、Maribel O. Marcarino、Agustina La-Venia
DOI:10.1021/acs.orglett.8b01567
日期:2018.7.6
A stereoselective multicomponent reaction involving Meldrum’s acid, a conjugated dienal, and an alcohol is reported. Valuable cyclopenta[b]furan-2-ones are obtained as products of this straightforward transformation, which is accompanied by the formation of four stereocenters, two new cycles, and four new bonds (two C–C and two C–heteroatom). A reaction mechanism was elaborated involving an initial
报道了涉及Meldrum酸,共轭二烯醛和醇的立体选择性多组分反应。作为这种直接转化的产物,获得了有价值的环戊[ b ]呋喃-2-酮,同时伴随着四个立体中心,两个新环和四个新键(两个C–C和两个C–杂原子)的形成。阐述了一种反应机理,包括最初的Knoevenagel缩合,然后进行环异构化和最终断裂。
Unprecedented stereoselective synthesis of cyclopenta[b]benzofuran derivatives and their characterisation assisted by aligned media NMR and 13C chemical shift ab initio predictions
作者:Martín J. Riveira、Chakicherla Gayathri、Armando Navarro-Vázquez、Nicolay V. Tsarevsky、Roberto R. Gil、Mirta P. Mischne
DOI:10.1039/c1ob05109a
日期:——
A new approach to the synthesis of cyclopenta[b]benzofuran derivatives via reaction of 1,3-dicarbonyl compounds with α,β,γ,δ-unsaturated aldehydes is described. The constitution and configuration of the new products have been firmly established by means of residual dipolar couplings (RDCs) and ab initio13C NMR chemical shift predictions.
本文介绍了一种通过 1,3-二羰基化合物与 α、β、γ、δ-不饱和醛反应合成环戊并[b]苯并呋喃衍生物的新方法。通过残余偶极耦合(RDC)和 ab initio13C NMR 化学位移预测,牢固地确定了新产物的组成和构型。
Mlochowski, J.; Abdel-Latif, F. F.; Kubicz, E., Polish Journal of Chemistry, 1993, vol. 67, # 4, p. 711 - 722
作者:Mlochowski, J.、Abdel-Latif, F. F.、Kubicz, E.、Said, S. B.
DOI:——
日期:——
Cycloisomerization of Conjugated Trienones and Isomeric 2<i>H</i>-Pyrans: Unified Strategy toward Cyclopenta[<i>b</i>]furans
作者:Martín J. Riveira、Gastón N. Quiroga、Ernesto G. Mata、Vincent Gandon、Mirta P. Mischne
DOI:10.1021/acs.joc.5b00818
日期:2015.6.19
Conjugated trienones and isomeric 2H-pyrans were found to engage in a novel cycloisomerization cascade toward cyclopenta[b]furan derivatives. Knoevenagel chemistry and pericyclic reactions meet again to expand the polyene-carbonyl manifold.