TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The mesh size of silica gel utilized for the purification of crude simvastatin to provide (I) is 40-400, preferably 100-200. The amount of silica gel utilized for batch treatment or silica gel filtration column is 0.5-50 wt/wt.%.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: In the process: hydrolysis of (II) to obtain (III) does not involve isolation of triol acid; (IV) is acylated with 2,2-dimethyl butyryl chloride in the presence of an organic base comprising triethylamine, diisopropylethylamine, pyridine, piperidine, pyrrolidine, dimethylaminopyridine or imidazole, preferably pyridine to obtain (V); 1-8 molar equivalents of pyridine is utilized; acylation of (IV) is carried out in non-hazardous and recyclable acyclic 5-10C hydrocarbon solvent utilized in the acylation of (IV) to give (V) is octane, n-heptane, heptanes, n-hexane, hexanes or pentane, preferably n-heptane; 0.5-4 molar equivalents of 2.2% dimethylbutyryl chloride is utilized for acylation; 0.01-1 molar equivalents of dimethylamino pyridine is utilized; (V) is prepared without the isolation of (III) and (IV) in a single organic solvent; and simvastatin obtained after desilylation is purified in one step by silica gel batch treatment or silica gel filtration column to provide (I). The desilylated simvastatin was purified in one step by silica gel treatment to provide (I). Preferred Components: The organic solvent is ethylacetate, butylacetate, diisopropylether, diethylether, tertiary butyl methyl ether, n-hexane, hexanes, cyclohexane, heptane, methanol, ethanol, 2-propanol, 1-propanol, tert-butanol and/or sec-butanol, preferably ethyl acetate-hexane mixture ACTIVITY - Antilipemic; Antiarteriosclerotic.    MECHANISM OF ACTION - 3-Hydroxy-3-methylglutaryl coenzyme A reductase.    EXAMPLE - Lovastatin (50 g) and sodium hydroxide (50 g) were taken in methanol (350 ml) and heated to reflux for 24 hours. Then, the reaction mass was concentrated completely which was followed by addition of water. The pH of the reaction mixture was then adjusted below 2 using concentrated hydrochloric acid and stirred for half an hour at ambient temperature. The precipitated solid (triol acid) was then filtered and washed with cold water. The wet triol acid was then taken in toluene (600 ml) and water was removed azeotropically. Then, the reaction mixture was cooled to 25-30 degrees C after which imidazole (31 g) followed by tert-butyldimethylsilylchloride (34.2 g) was added. The obtained reaction mixture was maintained at -85 degrees C for 2 hours and then cooled to room temperature. The reaction mixture was washed with 0.2N aqueous hydrochloric acid solution, 10% sodium bicarbonate solution and water, and then dried over sodium sulfate. To the dried toluene layer, dimethyl amino pyridine (1.4 g) and imidazole (18.5 g) were added at 20-25 degrees C under nitrogen atmosphere. The contents were stirred for 15 minutes at 20-25 degrees C after which 2,2-dimethylbutyryl chloride (36.7 g) was added at 20-25 degrees C. Then, the temperature of the reaction mixture was raised to reflux and was maintained at reflux for 24 hours. Then, the reaction mixture was brought to 20-25 degrees C and washed with 0.2N aqueous hydrochloric acid solution. The separated organic layer was then dried over sodium sulfate and concentrated completely under vacuum to give silylated simvastatin as brown oil. Silylated simvastatin (25 g) and tetrahydrofuran (360 ml) were added under stirring in a round bottom flask at 25-35 degrees C. The mixture was stirred for 15 minutes and acetic acid (21 g) was added. The reaction mass was cooled to 15-20 degrees C. A solution of tetrabutylammonium fluoride in tetrahydrofuran was added into the reaction mass and stirred for 30-35 hours at 18-22 degrees C. Then, the reaction mass was poured in water, dichloromethane was added, pH was adjusted to neutral with sodium bicarbonate solution, and the mixture was stirred for 30 minutes. The aqueous layer was separated and water was added to organic layer. The organic layer was separated and the obtained mixture was worked up to give 6(R)-(2-8'(S)-2",2"-dimethylbutyryloxy-2'(S), 6'(R)-dimethyl-1',2',6',8',8a'(R)-hexahydronapthyl-1'(S)-ethyl)-4-(R)-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one (simvastatin) (12.5 g).