Molecular hybridization-guided annulation reactions of isatins with 4-methylpent-3-en-2-one: A direct access to spirooxindole tetrahydropyranones

<p>An efficient molecular hybridization strategy has been utilized for the synthesis of pirooxindole tetrahydropyranones <b>3</b> through annulation reactions of isatins <b>1</b> with 4-methylpent-3-en-2-one <b>2</b>. Products consist of a pirooxindole tetrahydropyranone scaffold and propan-2-ether unit were smoothly obtained in moderate yields (up to 56% yield). The one-pot, two-step reaction, avoiding the isolation and purification of intermediates <b>C</b>, has proved to be a practical protocol. This protocol leads to new knowledge in the fields of both molecular complexity and the lead compound discovery.