Pravastatin 3-O-(tert-Butyldimethylsilyl) Dehydro-lactone-d3 is an impurity in the synthesis of 3α-Hydroxy Pravastatin-d3 Sodium Salt (H952312), which is a metabolite of Pravastatin, a competitive inhibitor of HMG-CoA reductase. Bioactive metabolite of mevastatin.