Efficient synthesis of gamma-DDB.

: Synthesis of gamma-DDB, which is another family member of gamma-DDB (dimethyl 4,4(')-dimethoxy-5,6,5('),6(')- dimethylenedioxybiphenyl-2,2(')-dicarboxylate), is described. The unsymmetric isomer (gamma-DDB) was constructed by a linker-directed intramolecular Ullmann coupling reaction, followed by the cleavage of the linker and re-esterification.