The total synthesis of the novel hydroxylated HMG-CoA reductase inhibitor dihydroeptastatin (7) is described. The key C-3 hydroxyl group is introduced via a Baeyer-Villiger reaction on the methyl ketone 17 which is obtained in three high-yielding steps from the known tricyclic lactone 12. In an isolated enzyme assay dihydroeptastatin had a similar IC50 to mevinolin but in cellular assays using Hep G2 and HES 9 cell lines, dihydroeptastatin was much less potent. No selectivity between the two cell lines was observed.