Used as a key chiral building block in the synthesis of statin-class cholesterol-lowering drugs. Its protected hydroxyl groups and defined stereochemistry allow for selective chemical transformations, enabling efficient construction of complex drug molecules. Commonly employed in pharmaceutical research and development to introduce the side chain found in atorvastatin and similar HMG-CoA reductase inhibitors. The isopropylidene group stabilizes the intermediate during synthesis and is later removed under mild acidic conditions. Valued for high enantiomeric purity and compatibility with multi-step synthetic routes.