[Admare]

Hi I got a reaction that I am supposed to figure out sutible reagents to (see picture)
. I have already figured out how to make (2) from (1) that was simple enough but I can't think of any way to make (3) from (2) in 4 steps.  R1 can be anything and R2 has to be an arryl(Ar) or an alkyne(CCR)
I do not except a complete answer but I would appreciate a tip in the right direction.
I have been searching for a solution in my course book and on the internet the whole day without finding any good solution. It has to be done before tommorow.
Any good chemist here that can help me?
Me and hetrocycle chemistry isnt really friends right now.

[Admare]

Hi again I have done some more thinking.
First i would like to say that my answer from 1->2 is 4-DMAP, THF, rt, overnight then NaHCO₃, H₂O, MeOH, 50C,1 h

and I am think about adding a bromine at the R2 position in (2) in some way and then replace it with a alkyne is that possible?

[Dan]

Hi again I have done some more thinking.
First i would like to say that my answer from 1->2 is 4-DMAP, THF, rt, overnight then NaHCO₃, H₂O, MeOH, 50C,1 h

So where did the Boc come from?

Also, what is R¹?