Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids
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2012
Authors
Bjelaković, Mira S.Krstić, Natalija M.
Milić, Dragana
Kop, Tatjana
Robeyns, Koen
Pavlović, Vladimir D.
Article (Published version)
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The present study is concerned with the oxidative behaviour of unsaturated and epoxy 5-oxo-5,10-secosteroids in the presence of m-CPBA or TFAA-UHP as oxidants in order to investigate potential parameters controlling the chemoselectivity and regioselectivity. In the study we discovered a striking difference in the chemical behaviour of stereoisomeric compounds, (Z)- and (E)-3 beta-acetoxy-5,10-secocholest-1(10)-en-5-ones, as well as 1S,10R- and 1R,10R-epoxides. The secoketones were oxidized with exclusively C-6 migration and Baeyer-Villiger rearrangement product formation, whereas their stereoisomers provided the ring-contracted products, without lactone formation. The preferred conformation of expanded and contracted rings was established by NOESY correlations. The structures of two obtained lactones were also confirmed by X-ray analysis. The mechanistic and stereochemical aspects of these transformations are discussed. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords:
5-Oxo-5,10-secosteroids / 5,10-Secosteroidal 5,6-lactones / m-CPBA / TFAA-UHP reagent / Baeyer-Villiger oxidationSource:
Tetrahedron, 2012, 68, 36, 7479-7488Publisher:
- Pergamon-Elsevier Science Ltd, Oxford
Funding / projects:
- Design, synthesis and investigations of fullerene based nanomolecular machines (RS-MESTD-Basic Research (BR or ON)-172002)
DOI: 10.1016/j.tet.2012.06.024
ISSN: 0040-4020
WoS: 000307698100029
Scopus: 2-s2.0-84864279987
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Hemijski fakultet / Faculty of ChemistryTY - JOUR AU - Bjelaković, Mira S. AU - Krstić, Natalija M. AU - Milić, Dragana AU - Kop, Tatjana AU - Robeyns, Koen AU - Pavlović, Vladimir D. PY - 2012 UR - https://cherry.chem.bg.ac.rs/handle/123456789/1329 AB - The present study is concerned with the oxidative behaviour of unsaturated and epoxy 5-oxo-5,10-secosteroids in the presence of m-CPBA or TFAA-UHP as oxidants in order to investigate potential parameters controlling the chemoselectivity and regioselectivity. In the study we discovered a striking difference in the chemical behaviour of stereoisomeric compounds, (Z)- and (E)-3 beta-acetoxy-5,10-secocholest-1(10)-en-5-ones, as well as 1S,10R- and 1R,10R-epoxides. The secoketones were oxidized with exclusively C-6 migration and Baeyer-Villiger rearrangement product formation, whereas their stereoisomers provided the ring-contracted products, without lactone formation. The preferred conformation of expanded and contracted rings was established by NOESY correlations. The structures of two obtained lactones were also confirmed by X-ray analysis. The mechanistic and stereochemical aspects of these transformations are discussed. (C) 2012 Elsevier Ltd. All rights reserved. PB - Pergamon-Elsevier Science Ltd, Oxford T2 - Tetrahedron T1 - Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids VL - 68 IS - 36 SP - 7479 EP - 7488 DO - 10.1016/j.tet.2012.06.024 ER -
@article{ author = "Bjelaković, Mira S. and Krstić, Natalija M. and Milić, Dragana and Kop, Tatjana and Robeyns, Koen and Pavlović, Vladimir D.", year = "2012", abstract = "The present study is concerned with the oxidative behaviour of unsaturated and epoxy 5-oxo-5,10-secosteroids in the presence of m-CPBA or TFAA-UHP as oxidants in order to investigate potential parameters controlling the chemoselectivity and regioselectivity. In the study we discovered a striking difference in the chemical behaviour of stereoisomeric compounds, (Z)- and (E)-3 beta-acetoxy-5,10-secocholest-1(10)-en-5-ones, as well as 1S,10R- and 1R,10R-epoxides. The secoketones were oxidized with exclusively C-6 migration and Baeyer-Villiger rearrangement product formation, whereas their stereoisomers provided the ring-contracted products, without lactone formation. The preferred conformation of expanded and contracted rings was established by NOESY correlations. The structures of two obtained lactones were also confirmed by X-ray analysis. The mechanistic and stereochemical aspects of these transformations are discussed. (C) 2012 Elsevier Ltd. All rights reserved.", publisher = "Pergamon-Elsevier Science Ltd, Oxford", journal = "Tetrahedron", title = "Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids", volume = "68", number = "36", pages = "7479-7488", doi = "10.1016/j.tet.2012.06.024" }
Bjelaković, M. S., Krstić, N. M., Milić, D., Kop, T., Robeyns, K.,& Pavlović, V. D.. (2012). Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids. in Tetrahedron Pergamon-Elsevier Science Ltd, Oxford., 68(36), 7479-7488. https://doi.org/10.1016/j.tet.2012.06.024
Bjelaković MS, Krstić NM, Milić D, Kop T, Robeyns K, Pavlović VD. Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids. in Tetrahedron. 2012;68(36):7479-7488. doi:10.1016/j.tet.2012.06.024 .
Bjelaković, Mira S., Krstić, Natalija M., Milić, Dragana, Kop, Tatjana, Robeyns, Koen, Pavlović, Vladimir D., "Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids" in Tetrahedron, 68, no. 36 (2012):7479-7488, https://doi.org/10.1016/j.tet.2012.06.024 . .