3,8-Dimethoxy-1-methyl-chromeno[5,4,3-cde]chromene-5,10-dione

6'-Hydroxy-5,5'-dimethoxy-6-methoxycarbonyloxy-3-methyl-biphenyl-2,2'-dicarboxylic acid dimethyl ester

dimethyl 6,6'-dibenzyloxy-5,5'-dimethoxybiphenyl-2,2'-dicarboxylate

6'-Benzyloxy-5,5'-dimethoxy-6-methoxycarbonyloxy-3-methyl-biphenyl-2,2'-dicarboxylic acid dimethyl ester