The total synthesis of madindoline A was achieved. The key step of the synthesis is a reductive coupling of an acid-sensitive hydroxyfuroindoline derivative and a sterically hindered aldehyde using Sn(OTf)(2)-NaBH(OAc)(3). After the reductive coupling, the derived trione was subjected to intramolecular condensation to construct a madindoline skeleton. (C) 2000 Elsevier Science Ltd. All rights reserved.
Novel stereoselective construction of a quaternary carbon: application to synthesis of the cyclopentenedione moiety of madindolines
摘要:
Enantioselective synthesis of the cyclopentenedione moiety of madindolines was achieved. Stereoselective construction of a quaternary carbon was realized by alkylation of an enolate possessing chiral auxiliary. Cyclopentenedione was derived from a triketone precursor by intramolecular condensation. (C) 2000 Elsevier Science Ltd. All rights reserved.