balancing organic reaction

[rbl999]

Okay--I have to propose a reaction for the demethylation of codeine into morphine, and I have no idea where to start. The cytochrome P₄₅₀ oxidase pathway (esp. CYP₂D₆) is responsible, and I think it is an oxidation (loss of hydrogen), but there is a loss of C also and I don't know where to go:
C₁₈H₂₁NO₃-->C₁₇H₁₉NO₃ + 2H+?

[peter]

It goes like that:

Code: Select all

C18H21NO3 + HX = C17H19NO3 + CH3X

Don not know what X is but this is a general form for a demethylation reaction.