The first total syntheses of ochnaflavone, an asymmetric biflavone consisting of apigenin and luteolin moieties, and the permethyl ether of 2,3,2'',3''-tetrahydroochnaflavone have been achieved. The key steps in the synthesis of ochnaflavone were the formation of a diaryl ether and ring cyclization of an ether-linked dimeric chalcone to assemble the two flavone nuclei. Optimal experimental cond...

Cyclocondensation between 4,4`-bis(4-chlorobenzenesulfonyl)biphenyl and catechol, with subsequent chromatographic separation of the reaction products, led to isolation four novel ether-sulfone macrocycles (cyclic dimer, -trimer, -tetramer -pentamer). Similarly, cyclocondensation catechol a seven-ring diketone/disulfone monomer allowed two new aromatic ether-ketone-sulfone macrocycles, cyclic di...