[1,1'-Biphenyl]-2,2'-diol,5-[(1,2,3,4-tetrahydro-6,7-dimethoxy-1-isoquinolinyl)methyl]-5'-[(1,2,3,4-tetrahydro-6,7-dimethoxy-2-methyl-1-isoquinolinyl)methyl]-,[R-(R*,R*)]-