Hey,
This is my starting material. Just trying to figure out something other than just organocuprate additions, so I tried to search Hosomi-Sakurai for esters.
Honestly, any conjugate addition to a,b-unsat. ester seems to be rare, let alone on a four membered ring. There is hardly anything on this topic. Would it be worth a shot, or is the reason for lack of literature that it just isnt working?