Two efficient cascade reactions to synthesize substituted furocoumarins.
We have developed two efficient one-pot reactions to generate furo[3,2-c]coumarins and chlorofuro[3,2-c]coumarins through addition/cyclization/oxidation and chlorination. One cascade addition/cyclization/oxidation sequence of 1 with H(2)O in the presence of 20% CuCl as Lewis acid under an air atmosphere generated the 2-substituted-4 H-furo[3,2-c]chromen-4-one 2. Another sequence in the presence of 10% CuBr and excess CuCl(2) as the oxidant afforded the 3-chloro-2-substituted-4 H-furo[3,2- c]chromen-4-one 3.
Cheng
Gang
G
Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, China.
Hu
Youhong
Y
D002384:Catalysis; D002713:Chlorine / Q000737:chemistry; D003500:Cyclization; D011564:Furocoumarins / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization
D011564:Furocoumarins; D002713:Chlorine