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@article{1411802, author = {Malatinsky, T. and Spisakova, M. and Babjak, M. and Dohanosova, J. and Marek, Jaromír and Moncol, J. and Fischer, R.}, article_location = {Weinheim}, article_number = {6}, doi = {http://dx.doi.org/10.1002/ejoc.201601488}, keywords = {Heterocycles; Nitrones; Carbohydrates; Cycloaddition; Diastereoselectivity}, language = {eng}, issn = {1434-193X}, journal = {European Journal of Organic Chemistry}, title = {Reversal of Stereoselectivity in Cycloadditions of Five-Membered Cyclic Nitrones Derived from Hexoses}, url = {https://onlinelibrary.wiley.com/doi/epdf/10.1002/ejoc.201601488}, volume = {2018}, year = {2017} }
TY - JOUR ID - 1411802 AU - Malatinsky, T. - Spisakova, M. - Babjak, M. - Dohanosova, J. - Marek, Jaromír - Moncol, J. - Fischer, R. PY - 2017 TI - Reversal of Stereoselectivity in Cycloadditions of Five-Membered Cyclic Nitrones Derived from Hexoses JF - European Journal of Organic Chemistry VL - 2018 IS - 6 SP - 1086-1098 EP - 1086-1098 PB - WILEY-VCH SN - 1434193X KW - Heterocycles KW - Nitrones KW - Carbohydrates KW - Cycloaddition KW - Diastereoselectivity UR - https://onlinelibrary.wiley.com/doi/epdf/10.1002/ejoc.201601488 N2 - Two five-membered cyclic nitrones derived from hexoses, a newly synthesized D-allo-configured nitrone and an already known D-talo-configured nitrone, have been examined in 1,3-dipolar cycloaddition reactions with vinyl acetate, allyl benzoate, methyl acrylate, acrylonitrile, and vinylene carbonate. The reactions of the D-allo-configured nitrone proceeded preferentially through the expected exo-anti transition state, but all the cycloadditions of the D-talo-configured nitrone surprisingly showed high exo-syn selectivity. This reversal of stereoselectivity has been explained by 3D analysis of the preferred conformations of the nitrones, obtained from X-ray data. The structures were further inspected using CONFLEX, PM5, and DFT calculations. All these methods revealed that the dioxolane substituents attached to C-5 of both nitrones had opposite spatial locations. ER -
MALATINSKY, T., M. SPISAKOVA, M. BABJAK, J. DOHANOSOVA, Jaromír MAREK, J. MONCOL a R. FISCHER. Reversal of Stereoselectivity in Cycloadditions of Five-Membered Cyclic Nitrones Derived from Hexoses. \textit{European Journal of Organic Chemistry}. Weinheim: WILEY-VCH, 2017, roč.~2018, č.~6, s.~1086-1098. ISSN~1434-193X. Dostupné z: https://dx.doi.org/10.1002/ejoc.201601488.
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