Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective gamma-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective gamma-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronudeophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective gamma-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts provided rapid access to optically enriched alpha,alpha-disubstituted alpha-amino acid derivatives, and the C-2-selective products led to facile synthesis of chiral N,O-acetals and gamma-lactols. Theoretical studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nudeophilic oxazolide and the electrophilic phosphonium intermediate.