Abstract Implementation of one of four inverse electron demand Diels-Alder reactions of 3- carbomethoxy-2-pyrones with N-vinyl-2-pyrrolidinone, vinylene carbonate, 1, 1- dimethoxyethylene or 1, 1, 2-trimethoxyethylene followed by choice of two standard reaction sequences:(1) removal of the carbomethoxy group (NaOH; copper powder, quinoline, Δ) or (2) its conversion to an acetate [NaOH:(CO) 2 Cl 2:(CH 3) 2 CuLi: m-CPBA] allows the ...