[Peptidecouple]

I have been asked to develop a synthetic scheme to L-Dopa starting with 3,4-dihydroxybenzyl bromide.  I need to develop two schemes, one using the amidomalonate method and one using the entioselective method (using N-amino-2-hydroxymethyl-2,3-dihydroindole. 

Working on the amidomalonate method right now.  I don't have much literature on this method and can't seem to find much on the net.  I just need some help getting started.  Looking at the starting material and the product, it is easy to see what is going on, the Br is cleaved off and the amid and carb. acid is attached at the C that the Br was cleaved from. 

Could I just form a carbocation on the C that is attached to the Carboxylic acid/amide group, and then the carbocation will attack the CH2 of the benzylbromide, kicking out the bromide by SN2.  Then we should have L-Dopa..correct or not?

As far as the enantioselective method, I haven't started on it yet, but once I finish the Amidomalonate method I think the second method will become more apparant.  Thanks for any help or suggestions. 

[agrobert]

How do you propose to generate a carbocation on the alpha carbon.  Also carbocations are electrophilic, not nucleophilic. You cannot attack benzyl bromide with a carbocation.