Formal synthesis of tautomycin, which inhibits type 1 and type 2A protein phosphatases, was achieved. Spiroketal diol 21 was synthesized from alcohol 2 or 11. The regioselective enzymatic acetylation of 21 with the lipase ‘Amano PS’ gave monoacetate 23 in 90% yield, which was converted into Ichihara's intermediate 31 based on Julia coupling and Wittig homologation.