Electrophilic aromatic substitution reaction of dihydrofuran-2,5-dione with anisole I am having trouble understanding the reaction of anisole with dihydrofuran-2,5-dione (succinic anhydride) in presence of $\ce{AlCl3}$ and acid works or how an electrophile is formed. I feel like the product should be something like $\ce{C11H12O4}$.
Nice! You've brought everything you need.

If you can't identify your electrophile immediately, do it the other way around: Assign function to all components. The one that is left must be your electrophile - or its precursor.

Do you remember the role of $\ce{AlCl3}$ in electrophilic aromatic substitutions? Where could it possible attack here?

Here is another hint: What is the trivial name for dihydrofuran-2,5-dione?