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Enantioselective total synthesis and structural assignment of callyspongiolide.

ABSTRACT: We have elucidated the complete absolute configuration of callyspongiolide and unambiguously assigned its stereochemistry at the C-21 center through synthesis. Four stereoisomers of callyspongiolide were synthesized in a convergent and enantioselective manner. A late-stage Sonogashira coupling forges the diene-ynic side chain. Other notable reactions are Yonemitsu's variation of Yamaguchi macrolactonization to cyclize an alkynic seco acid, highly trans-selective Julia-Kocienski olefination, CBS reduction to set the C-21 stereocenter, and methyl cuprate addition to an unsaturated pyranone to install the C-5 methyl center.

SUBMITTER: Ghosh AK

PROVIDER: S-EPMC5143229 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature

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Enantioselective total synthesis and structural assignment of callyspongiolide.

Ghosh Arun K AK Kassekert Luke A LA Bungard Joseph D JD

Organic & biomolecular chemistry 20161201 48

We have elucidated the complete absolute configuration of callyspongiolide and unambiguously assigned its stereochemistry at the C-21 center through synthesis. Four stereoisomers of callyspongiolide were synthesized in a convergent and enantioselective manner. A late-stage Sonogashira coupling forges the diene-ynic side chain. Other notable reactions are Yonemitsu's variation of Yamaguchi macrolactonization to cyclize an alkynic seco acid, highly trans-selective Julia-Kocienski olefination, CBS ...[more]

PMID: 27762414

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