Jump to main content
Jump to site search


Beyond optical rotation: what's left is not always right in total synthesis

Author affiliations

Abstract

This work describes the application of vibrational (VCD) and electronic (ECD) circular dichroism spectroscopy to solve the longstanding debate around the absolute configuration of (+)-frondosin B (1). The absolute configuration of (+)-1 could confidently be assigned as (R) using these spectroscopic techniques. The discrepancy in the optical rotation (OR) values obtained in previous studies can be attributed to an undetected minor impurity (ca. 7%) that arose unexpectedly in a key step late in the synthesis. Additionally, the conditions used in the final step of the previous reports for demethylation to form the natural product proceeded with significant loss of enantiopurity. The large OR measured for the impurity at its observed level, when compared to the small rotation for the less enantiopure natural product 1, led to a measured OR value for the synthetic material that had the opposite sign of the natural product.

Graphical abstract: Beyond optical rotation: what's left is not always right in total synthesis

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Sep 2017, accepted on 27 Oct 2017 and first published on 30 Oct 2017


Article type: Edge Article
DOI: 10.1039/C7SC04249C
Citation: Chem. Sci., 2018, Advance Article
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Beyond optical rotation: what's left is not always right in total synthesis

    L. A. Joyce, C. C. Nawrat, E. C. Sherer, M. Biba, A. Brunskill, G. E. Martin, R. D. Cohen and I. W. Davies, Chem. Sci., 2018, Advance Article , DOI: 10.1039/C7SC04249C

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements