NOVELTY - Preparation of simvastatin (VI) comprises reacting (1R, 5R)-6-((1S,2S,6R,8aR)-2,6-dimethyl-1,2,6,7,8,8a-hexahydro-naphthalen-1-yl)-4-hydroxy-2-(tetrahydro-pyran-2-yloxy)-hexanoic acid butylammide-2,2-dimethyl butylamide-2,2-dimethyl butyric acid (I) with an acid to form a 2-methyl-butyric acid (1S.3R,7S,8S,8aR)-8-((R)-5-((R)-butylcarbamoyl)-3-hydroxy-5-(tetrahydro-pyran-2-yloxy)-pentyl)-3,7-dimethyl-1,2,3,7,8,8a,-hexahydro-naphthalen-1-yl-ester (II).    USE - (VI) is useful: as a potent anti-hypercholesterolemic agent; to inhibit cholesterol biosynthesis; to inhibit 3-Hydroxy-3-methyl-glutaryl coenzyme A reductase; and to increase the number of cellular low density lipoprotein (LDL) receptors that remove the LDL cholesterol circulating in the blood and lower blood cholesterol levels. No biological data given.    ADVANTAGE - The process is ecofriendly, industrially well suited, commercially viable, reproducible and cost effective. The process involves hydroxy group-protected derivatives of lovastatin as intermediates having good stability, easily synthesizable, good yield and high purity.    DETAILED DESCRIPTION - Preparation of simvastatin comprises: reacting (1R, 5R)-6-((1S,2S,6R,8aR)-2,6-dimethyl-1,2,6,7,8,8a-hexahydro-naphthalen-1-yl)-4-hydroxy-2-(tetrahydro-pyran-2-yloxy)-hexanoic acid butylamide-2,2-dimethyl butylamide-2,2-dimethyl butyric acid (I) with an acid to form a 2,2-dimethyl-butyric acid (1S,3R,7S,8S,8aR)-8-((R)-5-((R)-butylcarbamoyl)-3,5-dihydroxy-pentyl)-3,7,-dimethyl-1,2,3,7,8,8a,-hexahydro-naphthalen-1yl-ester (II); methylating a 2-methyl-butyric acid (1S,3R,7S,8S,8aR)-8-((R)-5-((R)-butylcarbamoyl)-3-hydroxy-5-(tetrahydro-pyran-2-yloxy)-pentyl)-3,7-dimethyl-1,2,3,7,8,8a,-hexahydro-naphthalen-1-yl-ester (III) to give (I); or reacting lovoastatin with 3,4,-dihydro-2H-pyran to form an (S)-2-methyl-butyric acid (1S,3R,7S,8S,8aR)-3,7,-dimethyl-8(2-((R)-6-oxo-4-(tetrahydro-pyran-2-yloxy)-tetrahydro-pyran-2-yl)-ethyl)-1,2,3,7,8,8a-hexahydro-naphthalen-1-yl-ester intermediate (IV) and without isolating (IV), reacting with an amine to form (III), methylating (III) to form (I) and reacting with an acid to form (R)-7-(1S,2S,6R,8S,8aR)-2,6-dimethyl-8-((S)-2-methyl-butyryloxy)-1,2,6,7,8,8a-hexahydro-heptanoic acid (V).    INDEPENDENT CLAIMS are included for:    (1) (S)-2-methyl-butyric acid (1S,3R,7S,8S,8aR)-3,7,-dimethyl-8(2-((R)-6-oxo-4-(tetrahydro-pyran-2-yloxy)-tetrahydro-pyran-2-yl)-ethyl)-1,2,3,7,8,8a-hexahydro-naphthalen-1-yl-ester (IV);    (2) 2-methyl-butyric acid (1S.3R,7S,8S,8aR)-8-((R)-5-((R)-butylcarbamoyl)-3-hydroxy-5-(tetrahydro-pyran-2-yloxy)-pentyl)-3,7-dimethyl-1,2,3,7,8,8a,-hexahydro-naphthalen-1-yl-ester (III);    (3) (1R, 5R)-6-((1S,2S,6R,8aR)-2,6-dimethyl-1,2,6,7,8,8a-hexahydro-naphthalen-1-yl)-4-hydroxy-2-(tetrahydro-pyran-2-yloxy)-hexanoic acid butylamide-2,2-dimethyl butylamide-2,2-dimethyl butyric acid (I);    (4) a solid premix comprising (VI) and butylated hydroxyanisole; and    (5) a process for preparing a solid premix comprising combining a solution of (VI) with butylated hydroxyanisole and water.