Bisterfeld C, Holec C, Böse D, Marx P, Pietruszka J. Chemoenzymatic Total Synthesis of the Proposed Structures of Putaminoxins B and D.
JOURNAL OF NATURAL PRODUCTS 2017;
80:1563-1574. [PMID:
28445040 DOI:
10.1021/acs.jnatprod.7b00101]
[Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Different enzymatic and nonenzymatic approaches were tested and compared to afford enantiopure homoallylic and allylic alcohols as building blocks in a total synthesis showcase. Thereby, highly enantioselective alcohol dehydrogenases and the P450 BM3 monooxygenase variant A74G L188Q were compared to classical asymmetric reagent-controlled allyl additions. Thus, the first total syntheses of the proposed structures for putaminoxins B/D and their respective enantiomers were accomplished. Detailed spectroscopic analysis of the newly synthesized compounds unraveled a discrepancy with respect to the reported structures of putaminoxins B/D. Furthermore, it was demonstrated that total synthesis is generally required for unequivocal assignment of configuration, because purely comparative NMR studies and judgment by analogy can lead to false predictions.
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