Microwave-Assisted Improved Regioselective Synthesis of 12<i>H</i>-Benzopyrano[3,2-<i>c</i>][1]benzopyran-5-ones by Radical Cyclisation

<table>Bu<sub>3</sub>SnH, AIBN, PhMe, MWI (2.45 GHz, 1 h) in open vessel.</table>

Organic Chemistry International

Scheme 2: Microwave-Assisted Improved Regioselective Synthesis of 12<i>H</i>-Benzopyrano[3,2-<i>c</i>][1]benzopyran-5-ones by Radical Cyclisation 