An efficient one-pot synthesis of 5-acyl-1,2,3,4-tetrahydropyrimidine-
2-thiones/ones is described. The synthesis is based on the reaction of
readily available a-tosyl substituted thioureas or ureas with enolate
s of beta-oxoesters or 1,3-dicarbonyl compounds followed by acid-catal
yzed dehydration of the obtained -acyl-4-hydroxyhexahydropyrimidine-2-
thiones/ones.