Convenient synthesis and unusual reactivity of 2-oxo-2H,5H-pyrano[3,2-c]chromenes
作者:Margita Lácová、Henrieta Stankovičová、Andrej Boháč、Bibiána Kotzianová
DOI:10.1016/j.tet.2008.07.032
日期:2008.9
The reaction of 4-oxo-4H-chromen-3-carbaldehydes with coumarin-4-acetic acids under the Perkin conditions follows an interesting pathway that involves aldol reaction and subsequent intramolecular lactonization to afford 2-oxo-2H,5H-pyrano[3,2-c]chromene skeleton. In contrast to chromone-3-carbaldehydes, the same reaction with chromone-2-carbaldehydes yielded only the aldol condensation product. The reaction was performed under thermal and microwave conditions. The reactivity of 2-oxo2H,5H-pyrano[3,2-c]chromenes in water, alcohol and acetic acid was described. (C) 2008 Elsevier Ltd. All rights reserved.