eprintid: 10099095
rev_number: 8
eprint_status: archive
userid: 695
dir: disk0/10/09/90/95
datestamp: 2020-05-30 23:17:00
lastmod: 2020-05-30 23:17:00
status_changed: 2020-05-30 23:17:00
type: thesis
metadata_visibility: show
creators_name: Stones, Rachel S
title: Integration of racemisation for the CHMO catalysed synthesis of optically pure lactones
ispublished: unpub
keywords: Pure sciences; Applied sciences; Baeyer-Villiger reaction
note: Thesis digitised by ProQuest.
abstract: Traditional chemical procedures can be difficult to perform stereoselectively. Many reactions result in racemic products which require resolution and therefore a maximum of fifty percent product yield - to produce a single enantiomer. The temperature, pressure and reagents involved in many of these reactions make the scale-up of the process from bench to production scale difficult. Biotransformations can offer an alternative route to optically pure products from racemic starting materials, although they often suffer from low yields. The combination of a bioconversion and chemical racemisation could produce a step increase in the yield of enantiomencally pure products. This idea was explored within the research detailed in the thesis. A representative system in which a bioconversion and racemisation step can be combined to produce material with high enantiomeric excess and improved yield was chosen. The Baeyer-Villiger reaction involves the conversion of ketones (or cyclic ketones) to esters (or lactones). The reaction can be catalysed by the monooxygenase group of certain enzymes. The cyclohexanone monooxygenase (CHMO) catalysed bioconversion of a 2-substituted cyclic ketone was used as a model reaction for the combined process. The integrated process was compared with the traditional chemical procedure and the increasingly popular biotransformation. The integrated process was performed in two different type of reactor, a linked reactor and a membrane bioreactor. The process in the linked reactor was found to have no advantage over the chemical or biovconversion process, whilst the process performed in the membrane bioreactor had a significant advantage (in terms of yield and enantiomeric excess) over the chemical and bioconversion route.
date: 2000
oa_status: green
full_text_type: other
thesis_class: doctoral_open
thesis_award: Ph.D
language: eng
thesis_view: UCL_Thesis
primo: open
primo_central: open_green
verified: verified_manual
full_text_status: public
pages: 219
institution: UCL (University College London)
department: Chemical and Biochemical Engineering
thesis_type: Doctoral
citation:        Stones, Rachel S;      (2000)    Integration of racemisation for the CHMO catalysed synthesis of optically pure lactones.                   Doctoral thesis  (Ph.D), UCL (University College London).     Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10099095/1/Integration_of_racemisation_fo.pdf