Answer: Theoretical yield = mol of product/ moles of reactant.
This is an diene and dienophile reaction to form single product through cyclization reaction.
As the percentage conversation is not mention, so reaction will progress as long as limiting reagent is there.
Here the value of mole of reactant is decided by the limiting reagent.
This is an addition reaction of two components.
So, mol of product = mol of limiting reagent.
So, Theoretical yield is 100%.