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Formal synthesis of aspidosperma alkaloids via the intramolecular [3 + 2] cycloaddition of 2-azapentdienyllithiums.

ABSTRACT: [reaction: see text] A formal synthesis of the Aspidosperma alkaloids aspidospermidine, aspidospermine, and quebrachamine is reported through an efficient preparation of Stork's penultimate intermediate. The key step of the sequence involved an intramolecular [3 + 2] cycloaddition of the 2-azapentadienyllithium 21 formed in situ from the corresponding imine 1, which after N-alkylation of the resulting cycloadduct provided 2 in excellent yield. The synthesis represents a new disconnection of the classical tricyclic ketone used for appendage of the requisite indole.

SUBMITTER: Pearson WH

PROVIDER: S-EPMC2538914 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature

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Formal synthesis of aspidosperma alkaloids via the intramolecular [3 + 2] cycloaddition of 2-azapentdienyllithiums.

Pearson William H WH Aponick Aaron A

Organic letters 20060401 8

[reaction: see text] A formal synthesis of the Aspidosperma alkaloids aspidospermidine, aspidospermine, and quebrachamine is reported through an efficient preparation of Stork's penultimate intermediate. The key step of the sequence involved an intramolecular [3 + 2] cycloaddition of the 2-azapentadienyllithium 21 formed in situ from the corresponding imine 1, which after N-alkylation of the resulting cycloadduct provided 2 in excellent yield. The synthesis represents a new disconnection of the ...[more]

PMID: 16597135

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