Direct asymmetric synthesis of δ-hydroxy-β-ketoesters was accomplished via regio- and enantioselective aldol reactions of β-ketoesters with isatins catalyzed by cinchona alkaloid thiourea derivatives. The C–C bond formation of the reactions occurred only at the γ-position of the β-ketoesters. Reaction progress monitoring and product stability analyses under the conditions that included the catalyst indicated that the γ-position reaction products were formed kinetically. Various δ-hydroxy-β-ketoesters bearing 3-alkyl-3-hydroxyoxindole cores relevant to the development of bioactive molecules were synthesized.

[3 + 2] annulations of spirocyclopropyl oxindoles with ynamides to offer biologically important spirocyclopenteneoxindoles in high yields with good diastereoselectivities were developed.

1,3-Cyclohexandione derived cyclic ketals and thiol ketals were used as O- and S-nucleophiles, respectively for the ring opening of donor-acceptor cyclopropanes catalyzed by Cu(OTf)2 and a series of functionalized alkylene...

1,6-Dicarbonyl compounds, representing the formal addition products of the α-position of acetophenone derivatives to donor–acceptor cyclopropanes, were synthesized in two steps via first ring opening of donor–acceptor cyclopropanes with acyclic 1,3-diketones followed by DBU catalyzed retro-Claisen-type C–C bond cleavage reactions. In the first step, acyclic 1,3-diketones selectively worked as C-nucleophiles to add to donor–acceptor cyclopropanes. In the second step, the alkyl ketone part of the ring-opening products resulting from unsymmetrical 1,3-diketones was selectively cleaved in the presence of DBU in methanol.