I don't see why not. A 1st round pick is a 1st round pick. The problem is, you trade during the draft. I don't think you sign guys while your drafting.
You would literally have to trade, then sign, then give the pick over. If you signed before the draft, the Ravens would already have your first round pick and you couldn't trade back.
So, while I suppose it's possible. It's highly unlikely.
The answer is no. If an RFA has draft pick compensation attached, to sign him to an offer sheet, a team must have its original pick in that round or a better pick.
If not, then that team would have to work out a trade with his previous team.