A synthesis-enabled relative configurational assignment of the C31–C46 region of hemicalide. Issue 38 (21st April 2022)

• Record Type: Journal Article
• Authors: Stockdale, Tegan P.; Lam, Nelson Y. S.; Paterson, Ian
• Is Part Of: Chemical communications. Volume 58:Issue 38(2022)
• Page Start: 5729
• Page End: 5732
• Publication Date: 2022-04-21
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/d2cc01802k
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : Detailed NMR spectroscopic comparisons with a series of truncate candidates enables the structural elucidation of the C31–C46 region of hemicalide, reducing the number of possible diastereomers from over one million down to eight. Abstract : With 21 unknown stereocentres embedded in spatially separated stereoclusters, the cytotoxic polyketide hemicalide represents a seemingly intractible structural assignment problem. Herein, through the targeted synthesis of configurationally defined fragments, as well as "encoded" mixtures of diastereomers, the stereochemical elucidation of the C31–C46 region of hemicalide is achieved. Detailed NMR spectroscopic analysis of candidate fragments and comparison with the related hemicalide data strongly supported a 31, 32- syn, 32, 36- anti and 42, 46- anti relationship. In combination with previous work on hemicalide, this reduces the number of possible structural permutations down to a more manageable eight diastereomers.