A process of manufacturing of Rosuvastatin Potassium of formula (I) is disclosed. The process comprises the steps of (c) treating Rosuvastatin protected compound of formula (II) wherein R and R are same or different having C1-C4 carbon atom or hydrogen or R and R can combine together to afford a cyclic structure comprising a junction atom as carbon or metal atom such as Si (silicon) with an inorganic base of the kind such as herein described having potassium as cation in a suitable solvent to form Rosuvastatin potassium (b) isolating Rosuvastatin potassium.
