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Synthesis of the tricyclic indole alkaloids, dilemmaones A and B.

ABSTRACT: Dilemmaones A-C are naturally occurring tricyclic indole alkaloids possessing a unique hydroxymethylene or methoxymethylene substituent at the C2 position of the indole core and a C6-C7 fused cyclopentanone. Dilemmaone B has been prepared in 5 steps from 5-methylindan-1-one, and dilemmaone A has been prepared in 3 steps from a common precursor, 6-bromo-5-methyl-7-nitroindan-1-one. In both syntheses, key steps include a Kosugi-Migita-Stille cross coupling and a reductive cyclization using hydrogen gas and a transition metal catalyst.

SUBMITTER: Lambson KE

PROVIDER: S-EPMC7450541 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

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Synthesis of the tricyclic indole alkaloids, dilemmaones A and B.

Lambson Katharine E KE Dacko Christopher A CA McNeill Jeffrey M JM Akhmedov Novruz G NG Söderberg Björn C G BCG

Tetrahedron 20191021 49

Dilemmaones A-C are naturally occurring tricyclic indole alkaloids possessing a unique hydroxymethylene or methoxymethylene substituent at the C2 position of the indole core and a C6-C7 fused cyclopentanone. Dilemmaone B has been prepared in 5 steps from 5-methylindan-1-one, and dilemmaone A has been prepared in 3 steps from a common precursor, 6-bromo-5-methyl-7-nitroindan-1-one. In both syntheses, key steps include a Kosugi-Migita-Stille cross coupling and a reductive cyclization using hydroge ...[more]

PMID: 32863445

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