H. Rao, K. Geetha, M. Kamalraj
Oct 21, 2011
Citations
0
Influential Citations
16
Citations
Journal
Tetrahedron
Abstract
Abstract A combinatorial library of 4-(2-hydroxyaryl)-3-nitro-4H-chromenes was synthesized in high yield by C4-SMe substitution in N-alkyl/phenyl 4-(methylthio)-3-nitro-4H-chromen-2-amines with a variety of phenols. The reaction always provided C2 substitution in the phenol ring, dictated by hydrogen bond interactions between the phenolic hydroxyl group and the nitro group in 3-nitro-4H-chromenes. Reduction of the nitro group with concomitant hydrolysis of the enamine in 4-(2-hydroxyaryl)-3-nitro-4H-chromenes with Zn, Ac2O in AcOH furnished hybrid amino-acid lactone incorporating ortho-tyrosine and phenyl alanine moieties.