Synthesis of the Tetracyclic ABCD Ring Domain of Calyciphylline A-Type Alkaloids via Reductive Radical Cyclizations.
A tetracyclic compound with the ABCD ring framework of calyciphylline A-type alkaloids was synthesized from a cis-3a-methyloctahydroindole triggered by a 5-endo radical cyclization. The synthesis required two additional ring-forming steps: the construction of a seven-membered ring by aldol cyclization and the azabicyclic fragment by a radical ring closure of a trichloroacetamide-tethered enol acetate followed by a diastereoselective α-methylation of the lactam group.
Laboratori de Química Orgànica, Facultat de Farmàcia, IBUB, Universitat de Barcelona , Av Joan XXIII s/n, 08028 Barcelona, Spain.
Guilhem
G
Coussanes
Laboratori de Química Orgànica, Facultat de Farmàcia, IBUB, Universitat de Barcelona , Av Joan XXIII s/n, 08028 Barcelona, Spain.
Josep
0000-0002-5551-6720
J
Bonjoch