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[摘要]:The synthesis of the pyrrolopyrrole substructure of the isoquinocyclines is reported. The pentacyclic (CDEFG) substructure of isoquinocycline A and B, which contains an unusual 2,4,5,6-tetrahydropyrrolo[2,3-b]pyrrole (FG) connected via an N,O-spiro acetal to the anthraquinoid core of the isoquinocycline aglycon has been synthesized. Key steps were a nickel(0)-mediated hydrocyanation of an alkynone, the conversion of an O,O-acetal into an N,O-acetal, and an intramolecular amidine alkylation. |
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