A chiral scandium catalyst, prepared from scandium trifluoromethanesulfonate (Sc(OTf)(3)), (R)-(+)1,1'-bi-2-naphthol, and a tertiary amine in dichloromethane, was quite effective in the enantioselective Diels-Alder reactions of acyl-1,3-oxazolidin-2-ones with dienes, and the corresponding Diels-Alder adducts were obtained in high yields with high diastereo- and enantioselectivities.