Asymmetric Synthesis of Carbocycles by Intramolecular Conjugate Displacement & Synthetic Studies on Sorbicillactone A

• Author / Creator

  Sreedharan, Dinesh

• The first chapter of this thesis describes an intramolecular conjugate displacement (ICD) for the asymmetric synthesis of carbocycles using a carbon nucleophile. The precursors for ICD were synthesized by Morita-Baylis-Hillman reaction between (5R)-5-(l-menthyloxy)-2(5H)-furanone and aldehydes, which carry a geminal phenylthio groups in the γ or δ position. Acetylation of the resulting hydroxyl group, followed by oxidation of the phenylthio groups to phenylsulfonyl groups gave the desired ICD precursor which, on treatment with a base, underwent ring closure by intramolecular conjugate displacement. Hydrogenation, DIBAL-H reduction and desulfonylation releases an optically pure carbocycle. The second chapter describes studies aimed at the synthesis of the bioactive marine alkaloid sorbicillactone A. During this project, much of the carbon skeleton of sorbicillactone A was assembled, and studies to finish the total synthesis are in progress. The key reactions involved in this project are radical-mediated cyclization to synthesize the bicyclic core, 1,4 addition of a phenyldimethylsilyl unit, followed by trapping of the intermediate with methyl iodide and, finally, a one pot process for ketal protection and iodolactonization. After the successful installation of nitrogen at C-3, current research is directed at the installation of a methyl group at the same C-3 position.

• Subjects / Keywords

  • Sorbicillactone A
  • Asymmetric synthesis of carbocycles
  • Optically pure carbocycles
  • Intramolecular conjugate displacement

• Graduation date

  Spring 2014

• Type of Item

  Thesis

• Degree

  Doctor of Philosophy

• DOI

  https://doi.org/10.7939/R3RV0D79R

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.