Benzopyrans. Part 41. Reactions of 2-(2-dimethylaminovinyl)-1-benzopyran-4-ones with various dienophiles
作者:Chandra Kanta Ghosh、Samita Bhattacharyya、Chandreyi Ghosh、Amarendra Patra
DOI:10.1039/a903145f
日期:——
propiolate (EP) ultimately gives xanthenones 33, 34 and 37, respectively, the latter being admixed with flavone 43. Enamine 2, cyclisable to xanthenone 11, gives 33 and 35 with DMAD, and 37 and 44 with EP. Reaction of 3 with DMAD affords 36 exclusively.
A base-promoted desalicyloylative dimerization of 3-(1-alkynyl)chromones: An unusual approach to 2-alkynyl xanthones
作者:Fuchun Xie、Xuan Pan、Shijun Lin、Youhong Hu
DOI:10.1039/b925234g
日期:——
A novel base-promoted cascade desalicyloylative dimerization of 3-(1-alkynyl)chromones to produce 2-alkynyl xanthones has been developed. This tandem process involves multiple reactions, such as Michael additions/cyclizations/desalicyloylation without a transition metal catalyst and inert atmosphere.