Methods for Determination of Absolute Configurations of Chiral Diols by THENA Ester and NMR Shift Difference
Kulvadee Dolsophon
a
Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
,
Jakapun Soponpong
a
Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
,
Jittra Kornsakulkarn
b
National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Thailand Science Park, Phathumthani 12120, Thailand
,
Chawanee Thongpanchang
b
National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Thailand Science Park, Phathumthani 12120, Thailand
,
Tienthong Thongpanchang∗
a
Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand
› Author AffiliationsFinancial support from Mahidol University and the Thailand Research Fund (Grant BRG5480020), the Royal Golden Jubilee Ph.D. Programme (Grant PHD/0032/2554) to K.D. and T.T., the Center of Excellence for Innovation in Chemistry (PERCH-CIC), and the Development of Pharmaceuticals from Bioresources and Its Management (NRU) for J.S. are gratefully acknowledged.
Determination of the absolute configuration of chiral secondary diols by chiral derivatizing agent (CDA) and NMR shift difference is of great challenge due to the complication from the interference of the aromatic anisotropic shielding effect of the two CDAs in close proximity. In this work, tetrahydro-1,4-epoxynaphthalene-1-carboxylic acid (THENA) was introduced as an alternative CDA for diols to overcome such complexity. Since the deshielding effect of THENA is weaker than the shielding effect of other CDAs, THENA would allow the direct analysis of the chemical shift difference in determining the absolute configuration of the chiral diols. In addition, an analytical method based on Riguera’s model could also be used to confirm the assignment. With a good agreement between the assigned configuration based on both analytical models, the absolute configuration of the chiral diols could be assigned with reliability.
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References and Notes
1 New address: K. Dolsophon, Department of Chemistry and Center of Excellence for Innovation in Chemistry, Faculty of Science, Srinakharinwirot University, Bangkok 10110, Thailand.
2 New address: J. Soponpong, Chulalongkorn University Drug Discovery and Drug Development Research Center, Chulalongkorn University, Bangkok, Thailand.
3a
Allenmark S,
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8a
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Mycenadiols (compound B) were provided by Dr. Masahiko Isaka, see. 2014: 97 ; 909 (+)-Goniodiol (compound E) was provided by Prof. Dr. Patoomratana Tuchinda, see:
11 CCDC 2144692 contains the supplementary crystallographic data for this paper (excluding structure factors). The data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/structures.
12 Due to the sign distribution error, the absolute configuration of compounds B-i and B-ii might not be properly assigned by this model due to the small number of data points.
