1,6-Methano-3-benzazocine, 1,2,3,4,5,6-hexahydro-3-methyl-, (1R)-, ethanedioate (1:1) 136377-41-8 3-Methyl-1,2,3,4,5,6-hexahydro-1,6-methano-3-benzazocinium 3-Mhmb