of two mutually coupled doublets [δH7.21 and 6.46 (each 1H, d, J = 1.8 Hz)] and a one-proton singlet (δH 7.06), characteristic of the dehydrodigalloyl moiety(DHDG)
of two mutually coupled doublets [δH7.21 and 6.46 (each 1H, d, J = 1.8 Hz)] and a one-protonsinglet (δH 7.06), characteristic of the dehydrodigalloyl moiety(DHDG)