Tetrahedron Letters

An environmentally benign synthesis of aurones and flavones from 2′-acetoxychalcones using n-tetrabutylammonium tribromide

G Bose, E Mondal, AT Khan, MJ Bordoloi

Index: Bose, Gopal; Mondal, Ejabul; Khan, Abu T; Bordoloi, Manob J. Tetrahedron Letters, 2001 , vol. 42, # 50 p. 8907 - 8909

Full Text: HTML

Citation Number: 80

Abstract

A wide variety of aurones (3a–f) can be prepared exclusively from 2′-acetoxychalcones (1a– f) in high yields in two steps, by bromination using n-tetrabutylammonium tribromide (TBATB) in the presence of CaCO3 in CH2Cl2–MeOH (5: 2) at 0–5° C followed by cyclization of the brominated products 2a–f on treating with 0.2 M ethanolic KOH solution at 0–5° C, respectively. In contrast various flavone derivatives 6a–f can be obtained ...