[tefta10]

Please can someone tell me which is more polar : Benzylmorphine or Thebaine? thanks

[helenn]

Have you got the structures? What are the differences in the functional groups present in each molecule? One has more polar functional groups, see if you can figure out which.

[tefta10]

Thank you for answering. Yes, the structures can be googled as well.
This is of Thebaine:
http://en.wikipedia.org/wiki/Thebaine

and this if of Benzylmorphine:
http://en.wikipedia.org/wiki/Benzylmorphine

The structures are very similar except that Benzylmorphine contains a benzyl radical and an OH while Thebaine contains two OCH3 groups

[Doc Oc]

There's no benzyl radical, just a benzyl protected phenol.

So look at the two structures, what are the differences?  The phenolic oxygens.  On Thebaine they are both methylated.  In benzyl morphine, one phenol is benzylated, the other is unprotected.  So you have oxygen-carbon bonds vs oxygen-hydrogen bonds.  Which is more polar?

[tefta10]

so you let me know that benzylmorphine is more polar , but doesn't the benzene protected phenol overshadow the OH effect on benzylmorphine? that's what my professor told me.

anyway, thank you for answering back.

[Doc Oc]

Well, that's tricky, but I wouldn't have necessarily come to that conclusion.  I can see how you'd make that argument because methyl groups are very small compared to a big slab of lard like a benzyl group so their combined hydrophobic properties might seem less, but the ability to physically remove the proton from a phenol and make it a charged species would lead me to still assume that was the more polar compound.  Maybe I'm off base.  Sorry I can't give a more concrete answer.