A novel asymmetric synthesis of a (3<i>R</i>,5<i>S</i>)-dihydroxyhexanoic ester is described. The ester, which serves as the precursor for generating the side chain of rosuvastatin, is synthesized from <sc>d</sc>-glucose and subsequently coupled, under Wittig olefination conditions, with a phosphonium ylide derived from an appropriately substituted pyrimidine moiety. The coupling results in the formation of a precursor containing all the structural features of rosuvastatin. This precursor is converted into rosuvastatin calcium following a well-established procedure.