Michael addition of enolates of 2a and 2b to r,β-unsaturated esters took place selectively on different faces (Si and Re, respectively) of the double bond to give the corresponding products 4 and 5, respectively, with >98% de. Subsequent hydrolysis of these Micheal adducts gives 3,4-disubstituted γ-lactones with high enantiomeric excesses.The Michael addition reaction is one of the most important processes for C-C bond formation in organic synthesis. 1 A number of methods for asymmetric Michael addition were developed in the 1980s. 2 In previous reports, diastereoselective Michael addition reactions using R-amino acid derivatives as Michael donors have been examined as a method for introducing an R-substituent. 3 Stereoselective synthesis of an R-substituted R-hydroxy acid has been explored. 4 However, application of the Michael addition reaction with respect to the newly formed bond on the R-hydroxy acid derivative is quite rare 5 and has not been probed thoroughly. Recently, we have shown that chiral dioxolanones 2a and 2b, derived from 1, could be used for the preparation of enantiopure R-substituted R-hydroxy acids. 6 As a result, we decided to explore the diastereo-