A propionate-derived polyketide building block A whose 2-methyl-1, 3-diol moiety was built by a Ti (III)-mediated ring opening reaction of a trisubstituted 2, 3-epoxy alcohol precursor was employed as a common starting material for the syntheses of highly substituted tetrahydropyrans 1–5, the first one being the C20–C28 fragment of cytotoxic natural products, phorboxazoles.