Wittig olefination and thiol mediated 7-endo-trig radical cyclization: novel synthesis of oxepin derivatives
作者:K.C. Majumdar、Abu Taher
DOI:10.1016/j.tetlet.2008.10.134
日期:2009.1
Thiophenol-mediated 7-endo radical cyclization for the synthesis of seven-membered cyclic ethers is described. This method can be successfully applied to synthesize various benzoxepin derivatives, which are present in many natural products as building blocks. Alkenyl radicals are generated from easily available terminal alkynes and thiophenol.
Copper(I)-Catalyst-Free Approach for the Synthesis of Chromene-Fused Pyrido[3,2-d]pyrimidines by Lewis Acid Catalyzed Aza-Diels-Alder Reaction
作者:K. Majumdar、Sudipta Ponra、Sintu Ganai
DOI:10.1055/s-0030-1258768
日期:2010.10
Pyrido[3,2-d]pyrimidine derivatives have been synthesized by the hetero-Diels-Alder reaction of 5-amino-1,3-dimethyl uracil and O-propargylated salicylaldehyde. The reaction requires only a single-step operation and provides potentially bioactive polycyclic heterocycles in high yields (71-82%) from easily available starting materials.