6431-08-9Relevant articles and documents
Regioselective Access to Structurally Diverse Coumarin Analogues through Iron-Catalysed Annulation Reactions
Ren, Qiao,Kang, Jie,Li, Muyao,Yuan, Lujiang,Chen, Ruoyun,Wang, Lei
supporting information, p. 5566 - 5571 (2017/10/13)
A highly efficient iron-catalysed propargylation/alkyne oxacyclization/isomerization strategy is described. Biologically active furo[3,2-c]coumarins and pyrano[3,2-c]coumarins are expeditiously assembled in moderate to good yields and with a broad substrate scope. The regioselective access to different coumarins is mainly dependent on the terminal group of the secondary propargylic alcohol.
The Chemistry of Coumarin Derivatives Synthesis of 3-Alkyl-4-hydroxycoumarins by Reductive Fragmentation of 3,3'-Alkylidene-4,4'-dihydroxybis
Appendino, Giovanni,Cravotto, Giancarlo,Tagliapietra, Silvia,Ferraro, Stefano,Nano, Gian Mario,Palmisano, Giovanni
, p. 1451 - 1458 (2007/10/02)
Treatment of 3,3'-alkylidene-4,4'-dihydroxybis 1 with NaBH3CN in refluxing MeOH affords 3-alkyl-4-hydroxycoumarins 2 and 4-hydroxycoumarin (3; Scheme 1).The reaction may take place via hydride trapping of alkylidenechromandiones C formed from 1 in a retro-Michael reaction.Such a retro-Michael reaction of 1 might be biologically relevant.The presence of C during the reductive fragmentation 1 --> 2 is suggested by Diels-Alder and nucleophilic trapping of the alkylidenechromandiones C as well as from cross-over experiments with coumarins other than 3 (see Scheme 2).The reductive fragmentation of 1 allows the chemo- and regioselective synthesis of a variety of 3-alkyl-4-hydroxycoumarins 2 (see Table).
