Flow reactors for the continuous synthesis of garlic metabolites

Garlic secondary metabolites are organosulfur compounds that possess prophylactic properties. The chemical composition of garlic oil extracts consists of a combination of these compounds. The instability of a major component, allicin 5, limits the commercial viability of garlic oil extracts. \nThe synthesis of garlics organosulfur compounds has been performed in batch reactors. In this thesis, flow reactors were utilised to improve the throughput, reduce the operating conditions. \nThe thermolysis of allicin 5 is the solitary approach to produce the garlic metabolite, ajoene 14. Ajoene 14 has greater stability compared to allicin 5 that possesses interesting biological activity. The primary three-step synthesis investigated consisted of dialkyl polysulfide synthesis, subsequent oxidation and finally the terminal thermolysis. \nIn addition, other garlic metabolites have also been produced. The synthesis of unsymmetrical monosulfides and their subsequent oxidation was investigated using novel heterogeneous packed-bed flow reactors. The stable amino acid, alliin 15, is the precursor of allicin 5. Alliin 15 was also synthesised in homogeneous flow mode. The telescoped synthesis of alliin 15 was successfully completed using a semi-batch reactor. \nDevelopment of novel approaches to synthesise garlics organosulfur compounds is reported in this thesis. Finally, the flow reactor systems, experimental details and characterisation of the compounds are described.