A straightforward access to 5,6-dihydropyrimidin-4-ones as racemic mixtures or enantiopure diastereoisomers was achieved thanks to a multicomponent Knoevenagel-aza-Michael-Cyclocondensation reaction involving Meldrum's acid and isourea derivatives. This constitutes not only a novel MCR of the original Biginelli–Atwal condensation but allows the construction of dihydrouracyl derivatives known as biorelevant diazole architectures.