title: An efficient transformation of furano-hydroxychalcones to furanoflavones via base mediated intramolecular tandem O-arylation and C-O bond cleavage: a new approach for the synthesis of furanoflavones.
abstract: A new and efficient potassium carbonate mediated intramolecular tandem O-arylation followed by C-O bond cleavage of furano-hydroxychalcones is described. The treatment of furano-hydroxychalcones pongamol (1a) and ovalitenone (2a) with potassium carbonate in DMF led to the direct formation of the furanoflavones lanceolatin B (3ab) and pongaglabrone (4ab) in excellent yields. This is the first report on the cyclization of furano-hydroxychalcones via C-O bond cleavage (demethoxylation) to produce furanoflavonoids.
authors.affiliation: Natural Products Chemistry Division, CSIR-Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu 180001, India.
authors.forename: Rajni
authors.initials: R
authors.lastname: Sharma
authors.forename: Ram A
authors.initials: RA
authors.lastname: Vishwakarma
authors.forename: Sandip B
authors.initials: SB
authors.lastname: Bharate
mesh_terms: D001688:Biological Products / Q000138:chemical synthesis / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry; D002384:Catalysis; D002599:Chalcone / Q000737:chemistry*; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D003500:Cyclization; D047309:Flavones / Q000138:chemical synthesis* / Q000737:chemistry; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D011188:Potassium / Q000737:chemistry
chemical_list: D001688:Biological Products; D002254:Carbonates; D047309:Flavones; D005663:Furans; D002599:Chalcone; C037593:potassium carbonate; D011188:Potassium