Fig. 2: Oxygen-mediated oxidative coupling of flavones.
From: Oxygen mediated oxidative couplings of flavones in alkaline water
A Luteolin undergoes oxidative coupling reaction, under weakly alkaline water to give major product dicranolomin (2a) and minor products, philonotisflavone (2a′, structure not shown), dehydrohegoflavone B (2a′′) and distichumtriluteolin (3a), which could be obtained separately from the coupling of isolated 2a and luteolin with 42% isolated yield. B Intramolecular oxidative coupling 3a proceeds to give different isomers cyclotriluteolin (4a, 4a′, and 4a′′). C Illustration of molecular packing of 4a′ crystals. D Top view and side view of ORTEP plot of CTL 4a′.
