ABSTRACT Knoevenagel condensation of barbituric acids with aromatic aldehydes containing one or two formyl groups was carried out. 5-Arylidenebarbituric acids underwent smooth hetero-Diels-Alder (HDA) reactions with enol ethers to afford cis and trans diastereoisomers of pyrano[2,3-d]pyrimidine-2,4-diones and 5,5'-(1,4-phenylene)bis[2H-pyrano[2,3-d]pyrimidine-2,4(3H)-dione] derivatives in excel...

the adducts produced in the reaction between trialkyl phosphites and acetylenic esters were trapped by hydantoins to produce highly functionalized dialkyl 2-(2,5-dioxo-4,4-diphenylimidazolidin-1-yl) succinate in good yields.