2-Hydroxy Atorvastatin tert-Butyl Ester-d5 is an intermediate in the synthesis of Atorvastatin (A791750), a selective, competitive HMG-CoA reductase inhibitor. Atorvastatin is the only drug in its class specfically indicated for lowering both elevated LDL-cholesterol and triglycerides in patients with hypercholesterolemia.