(4R-cis)-6-[(Acetyloxy)methyl]-2,2-dimethyl-1,3-dioxane-4-acetic acid, 1,1-dimethylethyl ester

(4R-cis)-6-[(Acetyloxy)methyl]-2,2-dimethyl-1,3-dioxane-4-acetic acid, 1,1-dimethylethyl ester, often referred to by its CAS number 154026-95-6, is used mainly as a key chiral pharmaceutical intermediate in the synthesis of statin drugs, especially Rosuvastatin (Crestor), and related derivatives, serving as a building block for the complex side chain of these cholesterol-lowering medications.