(1S,3S,7S,8S,8aR)-3-Hydroxy-8-[2-[(2R,4R)-4-hydroxy-6-oxotetrahydro-2H-pyran-2-yl]ethyl]-7-methyl-1,2,3,7,8,8a-hexahydronaphthalen-1-yl (2S)-2-Methylbutanoate (Pravastatin Lactone)