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Anionic annulation of appropriate 2,3-disubstituted pyrroles with Michael acceptors provides an expedient route to densely substituted 7-hydroxyindoles. Intrinsic to the methodology, the resulting substituents are disposed in a fully regiocontrolled manner. The methodology is applicable to the synthesis of 7-hydroxybenzofurans. None of the indoles/benzofurans or pyrrole synthons synthesized in this study have hitherto been reported.

The anionic [4 + 2] annulation of 3-substituted furoindolones with dimethyl maleate provides an expedient route for the synthesis of the title carbazole alkaloids. The employment of this strategy in combination with a Krapcho reaction/retro-Kolbe–Schmitt reaction has culminated in the first total synthesis of the lactonic carbazoles harmandianamine A and furanoclausamine B and a brief total synthesis of ekeberginine from a prenylated furoindolone. An unusual fragmentation of an ester function during the annulation is also reported.

The cascade annulation-lactonization of phthalides with α-carboxyfurylacrylates in the presence of lithium hexamethyldisilazide (LiHMDS) provides both convergent and semiconvergent regioselective syntheses of neo-tanshinlactones in moderate yields. This methodology also offers an avenue for the direct syntheses of hitherto unreported 6-alkoxycarbonyl-substituted neo-tanshinlactones and their heterocyclic analogues. A new synthesis of 4-alkyl phthalides was developed on the basis of a combination of a Duff reaction and Furstner cross-coupling.

The synthesis of 9,10-dimethoxy-2-methyl-1,4-anthraquinone, an unusual quinone, was achieved in five steps from p-benzoquinone. A Kochi–Anderson radical methylation features as the key step in the synthesis. The chemistry of a cyclopropa-1,4-anthracenedione is also described. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)