Chiral saturated alanine- and glycine-derived 6-isopropyl-5-phenylmorpholin-2-ones 11 and 12 have been prepared and employed for the generation of carboxy-stabilized ylides in asymmetric 1,3-dipolarcycloadditionreactions under thermal conditions, with electron-deficient dipolarophiles bearing double and triple bonds. The cycloadducts are obtained with high stereocontrol and mainly with endo selectivity