Stereocontrolled Synthesis of Harzialactone A and Its Three Stereoisomers by Use of Standardized Polyketide Building Blocks

In this paper, we present a short and convenient synthesis of the natural product Harzialactone A and its three stereoisomers. In a three‐step synthesis starting from cheap and commercially available benzaldehyde, we created the small polyketidic compound with full control over its two stereogenic centers. To this end, we employed a chiral building block previously described by us, introducing the first stereogenic center through a Horner–Wittig reaction. The second stereogenic center was installed via stereocontrolled syn ‐ or anti ‐reduction with the corresponding β‐hydroxy ketone intermediates. Upon ozonolysis followed by oxidation the natural product and its stereovariants were produced with excellent enantio‐ and diastereopurities.