A direct and asymmetric syn-aldol reaction of Nacyl-1,3-oxazinane-2-thiones with dialkyl acetals from aromatic acetals in the presence of 2−5 mol % [DTBM-SEGPHOS]NiCl 2 , TMSOTf, and lutidine has been developed. It has been established that the oxazinanethione heterocycle, used for the first time as a scaffold in asymmetric carbon−carbon bond-forming reactions, can be smoothly removed to give access to a variety of enantiomerically pure compounds with high synthetic value.