The asymmetric synthesis of both enantiomers of the δ-lactone analogue of the antitumoral natural product γ-lactone muricatacin has been carried out. Initial attempts to also synthesize the natural product proved unsuccessful due to the poor reactivity of the Grignard reagent derived from 2-(bromomethyl)-1,3-dioxolane. The designed synthetic route enabled us to increase the ring size to generate the δ-lactone analogue employing Sharpless asymmetric epoxidation and ZrCl4-catalyzed intramolecular acetalization as the key steps.
Key words
muricatacin - asymmetric synthesis - zirconium tetrachloride - natural product analogues - δ-lactone