Strength by Joining Methods: Combining Synthesis with NMR, IR, and Vibrational Circular Dichroism Spectroscopy for the Determination of the Relative Configuration in Hemicalide

Gussem, Ewoud De; Herrebout, Wouter A.; Specklin, Simon; Meyer, Christophe; Cossy, Janine; Bultinck, Patrick

doi:10.1002/chem.201404822

Cited by 26 publications

(28 citation statements)

References 49 publications

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“…Interestingly, only in 33 % of the cases were the NMR shielding tensors computed at the level of theory reported in the seminal publication (B3LYP/6‐31G(d,p)//MMFF) –. In the remaining 67 %, the geometry optimization steps was conducted at higher levels, such as B3LYP or mPW1PW91 DFT functionals, coupled with double‐ or triple‐ζ basis sets –. Hereafter, three representative examples of the use of CP3 in solving different types of structural problems are given.…”

Section: Cp3mentioning

confidence: 99%

Computational Chemistry to the Rescue: Modern Toolboxes for the Assignment of Complex Molecules by GIAO NMR Calculations

Grimblat

Sarotti

2016

Chemistry A European J

189

147

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The calculations of NMR properties of molecules using quantum chemical methods have deeply impacted several branches of organic chemistry. They are particularly important in structural or stereochemical assignments of organic compounds, with implications in total synthesis, stereoselective reactions, and natural products chemistry. In studying the evolution of the strategies developed to support (or reject) a structural proposal, it becomes clear that the most effective and accurate ones involve sophisticated procedures to correlate experimental and computational data. Owing to their relatively high mathematical complexity, such calculations (CP3, DP4, ANN-PRA) are often carried out using additional computational resources provided by the authors (such as applets or Excel files). This Minireview will cover the state-of-the-art of these toolboxes in the assignment of organic molecules, including mathematical definitions, updates, and discussion of relevant examples.

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Section: Cp3mentioning

confidence: 99%

Computational Chemistry to the Rescue: Modern Toolboxes for the Assignment of Complex Molecules by GIAO NMR Calculations

Grimblat

Sarotti

2016

Chemistry A European J

189

147

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“…179 The formation of aggregates and/or solute-solvent complexes in chiral natural products occurring as carboxylic acids makes the use of chiroptical methods more challenging. 188 The effects of this approach on VCD, ECD, and OR properties were evaluated using the acid form of 164 and (+)-(2S,3R)-hibiscus acid (166).…”

Section: Miscellaneousmentioning

confidence: 99%

Recent advances in the use of vibrational chiroptical spectroscopic methods for stereochemical characterization of natural products

2015

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“…Nevertheless, successful attempts exist for the absolute configuration assignment of large and flexible molecules. 17,22,23 In such cases, the use of other methods such as the synthesis of model compounds based on well-established reactions or NMR studies, are helpful for structure elucidation. Herein, the assignment of the C11 center of natural plakinidone derivative 1 was ascertained by enantioselective syntheses of fragment 5 .…”

Section: Introductionmentioning

confidence: 99%

Reassignment of the absolute configuration of plakinidone from the sponge consortium Plakortis halichondrioides–Xestospongia deweerdtae using a combination of synthesis and a chiroptical approach

Jiménez-Romero

Rode

Rodrı́guez

2016

Tetrahedron: Asymmetry

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Recent work by Wu et al. in connection with the first synthesis of the marine natural product plakinidone revealed that the most salient feature of its purported structure, a six-membered perlactone moiety, was in fact a five-membered lactone, i.e. a 3-methyl-4-hydroxy-2(5H)-furanone or tetronic acid ring. With the planar structure of plakinidone confidently revised, we undertook a new investigation to unambiguously establish its absolute configuration. Upon preparing two stable derivatives 1 and 5 from a sample of naturally occurring plakinidone extracted from the sponge association Plakortis halichondriodes–Xetospongia deweerdtae, the absolute configuration was assigned by synthesis and vibrational and electronic circular dichroism (VCD and ECD) measurements in combination with density functional theory calculations at the B3LYP/aug-cc-pVDZ/PCM(CH3CN) level of theory. Our combined efforts and the agreement between the experimental and calculated VCD/ECD spectra of 1 revealed that the absolute configuration of plakinidone was in fact (11S,17R) and not the formerly reported (11S,17S) diastereomer assigned by Wu et al.. Therefore, we propose that natural plakinidone is accurately represented by structure 12.

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Strength by Joining Methods: Combining Synthesis with NMR, IR, and Vibrational Circular Dichroism Spectroscopy for the Determination of the Relative Configuration in Hemicalide

Cited by 26 publications

References 49 publications

Computational Chemistry to the Rescue: Modern Toolboxes for the Assignment of Complex Molecules by GIAO NMR Calculations

Computational Chemistry to the Rescue: Modern Toolboxes for the Assignment of Complex Molecules by GIAO NMR Calculations

Recent advances in the use of vibrational chiroptical spectroscopic methods for stereochemical characterization of natural products

Reassignment of the absolute configuration of plakinidone from the sponge consortium Plakortis halichondrioides–Xestospongia deweerdtae using a combination of synthesis and a chiroptical approach

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