Synthesis of pyrroloquinolines as indole analogues of flavonols.
7-Acetyl-4,6-dimethoxy-3-phenylindole 10 was converted into a range of 7-indolyl chalcones 13 by reaction with aryl aldehydes under basic conditions. Oxidation of the chalcones 13 with alkaline hydrogen peroxide gave the isolable epoxides 14, which were cyclized with further base treatment into the indole flavonols, or 5-hydroxy-6-oxopyrroloquinolines 15. The related compounds 25 and 26, examples of indole flavanones and flavones, respectively, were also synthesized. UV spectroscopic comparisons between flavonoids and indole flavonoids are discussed.
Black
David StC
DS
School of Chemistry, The University of New South Wales, UNSW Sydney, NSW 2052, Australia. d.black@unsw.edu.au
Kumar
Naresh
N
Mitchell
Peter S R
PS