Diastereoselective samarium(II) iodide-mediated cascade radical cyclisations of methylenecyclopropane derivatives : a synthesis of (+-)-paeonilactone B
Diastereoselective samarium(II) iodide-mediated cascade radical cyclisations of methylenecyclopropane derivatives : a synthesis of (+-)-paeonilactone B
This thesis is concerned with the synthesis, and radical cyclisations of compounds containing a methylenecyclopropane moiety. Special interest is given to developing the samarium(II) iodide-mediated cascade cyclisation of methylenecyclopropyl ketones, which proceeds with high diastereoselectivity in the presence of HMPA, and provides a short route to paeonilactone (103).
Chapter 1 describes the synthesis of methylenecyclopropane derivatives, and the investigation into their cyclisations employing 1,5-hydrogen atom transfer, deselenation of acyl selenides, samarium(II) iodide and Cossy photolysis methodology. (Fig. 6202A)
Chapter 2 describes the diastereoselectivity study of samarium(II) iodide-mediated cascade radical cyclisations of methylenecyclopropyl ketones 209 and 210. The cascade was found to proceed in high yield and diastereoselectivity, which was dependent on the presence of HMPA and DMPU. (Fig. 6202B)
Chapter 3 reports the total synthesis of (±)-paeonilactone B (103) from bicyclic ether 211.
Chapter 4 details the diastereoselective samarium(II) iodide cascade radical cyclisation of allyl ethers 269 and 270, with the formation of the unexpected dimer 274. (Fig. 6202C)
The bicyclic ethers 272 and 273 were converted into (±)-1-epi-paeonilactone A (300). (Fig. 6202D)
Chapter 5 outlines the preliminary investigations into developing the samarium(II) iodide-mediated cascade radical cyclisation for the synthesis of other polycyclic skeletons.
University of Southampton
1998
Boffey, Raymond John
(1998)
Diastereoselective samarium(II) iodide-mediated cascade radical cyclisations of methylenecyclopropane derivatives : a synthesis of (+-)-paeonilactone B.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
This thesis is concerned with the synthesis, and radical cyclisations of compounds containing a methylenecyclopropane moiety. Special interest is given to developing the samarium(II) iodide-mediated cascade cyclisation of methylenecyclopropyl ketones, which proceeds with high diastereoselectivity in the presence of HMPA, and provides a short route to paeonilactone (103).
Chapter 1 describes the synthesis of methylenecyclopropane derivatives, and the investigation into their cyclisations employing 1,5-hydrogen atom transfer, deselenation of acyl selenides, samarium(II) iodide and Cossy photolysis methodology. (Fig. 6202A)
Chapter 2 describes the diastereoselectivity study of samarium(II) iodide-mediated cascade radical cyclisations of methylenecyclopropyl ketones 209 and 210. The cascade was found to proceed in high yield and diastereoselectivity, which was dependent on the presence of HMPA and DMPU. (Fig. 6202B)
Chapter 3 reports the total synthesis of (±)-paeonilactone B (103) from bicyclic ether 211.
Chapter 4 details the diastereoselective samarium(II) iodide cascade radical cyclisation of allyl ethers 269 and 270, with the formation of the unexpected dimer 274. (Fig. 6202C)
The bicyclic ethers 272 and 273 were converted into (±)-1-epi-paeonilactone A (300). (Fig. 6202D)
Chapter 5 outlines the preliminary investigations into developing the samarium(II) iodide-mediated cascade radical cyclisation for the synthesis of other polycyclic skeletons.
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Published date: 1998
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Local EPrints ID: 463440
URI: http://eprints.soton.ac.uk/id/eprint/463440
PURE UUID: 9718a06b-3a75-4365-a622-561ba64cde88
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Date deposited: 04 Jul 2022 20:51
Last modified: 04 Jul 2022 20:51
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Author:
Raymond John Boffey
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