Okilactomycin and chrolactomycin are novel polyketide antitumor antibiotics isolated from Streptomyces that differ only at their C(11) substituent.  Both natural products display significant in vitro growth inhibition activity against several cancer cell lines.  More importantly, okilactomycin was active in vivo against Ehrlich ascites carcinoma.  Recently, we initiated efforts to develop a convergent, stereocontrolled synthesis of both polyketides via a common late-stage intermediate.  Current achievements include a highly diastereoselective anionic oxy-Cope/hydroxylation sequence to set both the C(1) and C(13) stereogenicity of the cyclohexane fragment and application of the Petasis-Ferrier rearrangement to construct the 2,6-cis-tetrahydropyranone.  A summary of these results and additional progress will be presented.