This study commenced with an investigation into a total synthesis of the antibiotic platensimycin 1.1 in chapter one. The key reaction for accessing the synthetically challenging fused ring system involved a meta-photocycloaddition reaction and the chapter one describes our attempts at the syntheses of the key substrates. Much of the chemistry was unsuccessful however we were able to attempt a key photochemical reaction however the desired compound was not obtained. On the basis of these outcomes we refocused our efforts towards the syntheses of kainic acid 2.1 and allokaininc acid 2.2 in chapter two. We aimed to devise a stereoselective synthesis of both kainic acid 2.1 and the allokainic acid 2.2, utilising the diastereofacial selectivity inherent in the previously synthesised oxazolidinone 2.240. Oxazolidinone 2.240 was subjected to a stereo and regiocontrolled 1,3-dipolar cycloaddition to give isoxazole 2.279. Reduction, followed by dehydration of isoxazole 2.279 gave the enone 2.287 which forms the Michael acceptor in the key Michael addition reaction. The 1,4 addition on enone 2.287, gave the two diastereomers 2.328 and 2.329 which underwent sequential Wittig reaction, and Krapcho decarboxylation to give the formal synthesis of allokainic acid 2.2 and epikainate 2.346 respectively. An investigation was also conducted with the aim of altering the stereochemistry of the dicarboxylic group in compound 2.329, in order to produce a novel route to the stereoselective synthesis of kainic acid 2.1.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:595714 |
| Date | January 2014 |
| Creators | Panta, Raghava Reddy |
| Publisher | University of Sussex |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://sro.sussex.ac.uk/id/eprint/47474/ |
Page generated in 0.0114 seconds