One-Flask Tethered Ring Closing Metathesis-Electrocyclic Ring Opening for the Highly Stereoselective Synthesis of Conjugated Z/E-Dienes
作者:Bernd Schmidt、Oliver Kunz
DOI:10.1002/ejoc.201101497
日期:2012.2
A one-flask reaction sequence comprising ringclosing metathesis (RCM) of butenoates derived from allylic alcohols and a base-mediated ringopening gives 2Z,4E-configured dienoic acids in high yields and stereoselectivities. Application of the method to the synthesis of the natural product fusanolide A suggests that the originally published structure was erroneously assigned and should be revised.
包括衍生自烯丙醇的丁烯酸酯的闭环复分解 (RCM) 和碱介导的开环的单瓶反应序列以高产率和立体选择性得到 2Z,4E 构型的二烯酸。该方法在天然产物 fusanolide A 的合成中的应用表明最初发表的结构被错误地分配,应该进行修改。
Stereoselective Synthesis of 2Z,4E-Configured Dienoates through Tethered Ring Closing Metathesis
作者:Bernd Schmidt、Stephan Audörsch、Oliver Kunz
DOI:10.1055/s-0035-1562536
日期:——
is described. The sequence involves Steglich esterification of the reactants, followed by a one-pot ringclosing metathesis–base induced elimination–alkylation reaction to furnish the products in high stereoselectivity. Trapping of the intermediate sodium carboxylates is accomplished efficiently using Meerwein’s salt Et3OBF4. A two-step sequence leading from racemic allylic alcohols and vinylacetic
α,β-Unsaturated δ-Valerolactones through RCM-Isomerization Sequence
作者:Bernd Schmidt、Oliver Kunz
DOI:10.1055/s-0031-1290488
日期:2012.4
alpha,beta-Unsaturated d-lactones are accessible via a sequential ring-closing metathesis (RCM) double-bond migration reaction starting from butenoates of allyl alcohols. This approach proceeds efficiently with lower catalyst loadings and higher initial substrate concentrations compared to the alternative RCM of acrylates derived from homoallylic alcohols.