[sally]

How the deprotection accomplished (in terms of mechanism)? according to the article it occured with metal lithium and naphthalene at room temperature under N2, and what's the properties of the protection?

[movies]

These are relatively common reducing conditions for removing a benzyl ether protective group.  Do you have any ideas on the mechanism?  It is a bit complicated, but not too bad.

[sally]

not at all

[movies]

Are you familiar with the Birch reduction?

[sally]

I think I do, It's a radical reduction of alkenes and alkynes with Na and NH3

[sally]

how it's relevant to the mechanism of the deprotection?

[movies]

The Brich conditions can also reduce aromatic systems in a similar fashion.  Think about dumping an electron into the aromatic ring.  Where does that get you?

[Organishe]

I have an idea/hint, no idea if it is correct, but I'll give it a stab. The lithium reduces the napthalene via a SET, then the reduced napthalene species interacts with the benzyl ether PG?  I'm not sure how the mechanism goes from there though, but I'm going to guess some pi-pi interactions between the benzyl ether and napthalene, and then maybe a hydride transfer from somewhere to form toluene (from the benzyl PG). Close? 

[movies]

The metal does indeed reduce the napthalene to the radical anion, but that is more just to "solubilize" the electron.  Usually Birch reductions are done in NH₃ solvent, which can do the solvation by itself, but in more organic solvents like THF, the napthalene helps the electron along.

You idea about the pi-pi interactions is a good one, and is kind of close to reality, probably.  I think of the napthalene as more of a shuttle for the electron though: first it receives the e^- via SET, and then delivers the e^- via another SET to the substrate.