(5alpha,6alpha)-7,8-Didehydro-4,5-epoxy-3,6-dimethoxy-17-methylmorphinan 2859-16-7 Codeine methyl ether EINECS 220-674-1 Morphinan, 7,8-didehydro-3,6-alpha-dimethoxy-4,5-alpha-epoxy-17-methyl- O(6)-Codeine methyl ether