Abstract
Potassium ferricyanide oxidation of dl-4'-O-methyl-N-methylcoclaurine (VII) afforded two species of diphenyl ether derivatives (Base A'and Base B'), which were racemic and diastereoisomeric each to each. The yield was about 15%. Spectrometric studies of the dimerization product and their O-methyl ethers gave proof to their structures. The structures were confirmed by a synthesis of their O-methyl ethers via an alternative route. Configurations of the products were also assigned by the chemical correlation with fangchinoline, having (L, L)-configuration on the two asymmetric carbon atoms.
