Alcohol Mediated Synthesis of 4-Oxo-2-aryl-4<i>H</i>-chromene-3-carboxylate Derivatives from 4-Hydroxycoumarins
作者:Manoj R. Zanwar、Mustafa J. Raihan、Sachin D. Gawande、Veerababurao Kavala、Donala Janreddy、Chun-Wei Kuo、Ram Ambre、Ching-Fa Yao
DOI:10.1021/jo301044y
日期:2012.8.3
The unusual alcohol mediated formation of 4-oxo-2-aryl-4H-chromene-3-carboxylate (flavone-3-carboxylate) derivatives from 4-hydroxycoumarins and β-nitroalkenes in an alcoholic medium is described. The transformation occurs via the in situ formation of a Michael adduct, followed by the alkoxide ion mediated rearrangement of the intermediate. The effect of the different alcohol and nonalcohol media on
One-pot synthesis of 2-aryl-3-alkoxycarbonyl chromones through a cascade Lewis acid-catalyzed aldehyde olefination/oxa-Michael addition/oxidation
作者:Ningning Wang、Shuying Cai、Chao Zhou、Ping Lu、Yanguang Wang
DOI:10.1016/j.tet.2012.11.008
日期:2013.1
were effectively constructed from aryl aldehydes and 3-(2-(methoxymethoxy)phenyl)propiolates via a cascade Lewis acid catalyzed phenol ether deprotection/aldehyde olefination/intramolecular oxa-Michael addition reaction, and a sequential oxidation. This four-step reaction could be conducted in one-pot with high atom efficiency.