[3,4′-Bibenzofuran]-6,6′-diol, 3′-(3,5-dihydroxyphenyl)-2,2′,3,3′-tetrahydro-2,2′-bis(4-hydroxyphenyl)-4-[(1Z)-2-(4-hydroxyphenyl)ethenyl]-, (2S,2′R,3S,3′R)-