Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters
Enzymes as tools in organic synthesis have provided enormous advantages. This thesis deals with the applications of enzymes in the kinetic resolutions of racemic compounds. The stereochemistry of chiral compounds and the kinetics of α/β hydrolase lipases are presented. From a practical point of view...
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KTH, Organisk kemi
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ftkthstockholm:oai:DiVA.org:kth-424 2023-05-15T13:39:26+02:00 Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters Liu, Rong 2005 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-424 eng eng KTH, Organisk kemi Stockholm : KTH Trita-IOK, 1100-7974 2005:96 http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-424 urn:isbn:91-7178-129-3 info:eu-repo/semantics/openAccess enzyme kinetic resolution enantioselectivity lipase diastereoselectivity epimerisation metal-catalysed transformation intramolecular alkylation Other Basic Medicine Annan medicinsk grundvetenskap Doctoral thesis, comprehensive summary info:eu-repo/semantics/doctoralThesis text 2005 ftkthstockholm 2022-08-11T12:40:42Z Enzymes as tools in organic synthesis have provided enormous advantages. This thesis deals with the applications of enzymes in the kinetic resolutions of racemic compounds. The stereochemistry of chiral compounds and the kinetics of α/β hydrolase lipases are presented. From a practical point of view, the handling of a large number of parameters that influences the kinetic resolutions, especially enantioselectivity (E-value) are systematically described. A variety of approaches employed for raising the yields to over 50% are additionally discussed. Methods for the preparation of synthetically useful chiral building blocks were developed in this thesis. Thus, resolution of secondary alcohols bearing two vicinal stereocentres are studied. These building blocks can serve as starting materials for the synthesis of various enantiomerically pure compounds for agrochemistry, pharmaceuticals, chemical industry, and particularly for the total synthesis of pheromones. Racemic 3-substitued 2-hydroxybutane derivatives were produced in fairly high diastereomeric purities by a variety of chemical approaches, such as epimerization, metal-catalysed asymmetric addition etc. Kinetic resolution of these racemates was achieved by enzyme-catalysed reactions. Two lipases, Candida antarctica lipase B and Pseudomonas cepacia lipase were found to be useful in acylations as well as hydrolyses. In the biotransformations studied, the presence and nature of the second vicinal stereocentre in the chiral secondary alcohols investigated seemed to be important, e.g. in terms of the efficiencies of sequential kinetic resolutions, and altering the selectivities as well. QC 20101020 Doctoral or Postdoctoral Thesis Antarc* Antarctica Royal Institute of Technology, Stockholm: KTHs Publication Database DiVA |
institution |
Open Polar |
collection |
Royal Institute of Technology, Stockholm: KTHs Publication Database DiVA |
op_collection_id |
ftkthstockholm |
language |
English |
topic |
enzyme kinetic resolution enantioselectivity lipase diastereoselectivity epimerisation metal-catalysed transformation intramolecular alkylation Other Basic Medicine Annan medicinsk grundvetenskap |
spellingShingle |
enzyme kinetic resolution enantioselectivity lipase diastereoselectivity epimerisation metal-catalysed transformation intramolecular alkylation Other Basic Medicine Annan medicinsk grundvetenskap Liu, Rong Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
topic_facet |
enzyme kinetic resolution enantioselectivity lipase diastereoselectivity epimerisation metal-catalysed transformation intramolecular alkylation Other Basic Medicine Annan medicinsk grundvetenskap |
description |
Enzymes as tools in organic synthesis have provided enormous advantages. This thesis deals with the applications of enzymes in the kinetic resolutions of racemic compounds. The stereochemistry of chiral compounds and the kinetics of α/β hydrolase lipases are presented. From a practical point of view, the handling of a large number of parameters that influences the kinetic resolutions, especially enantioselectivity (E-value) are systematically described. A variety of approaches employed for raising the yields to over 50% are additionally discussed. Methods for the preparation of synthetically useful chiral building blocks were developed in this thesis. Thus, resolution of secondary alcohols bearing two vicinal stereocentres are studied. These building blocks can serve as starting materials for the synthesis of various enantiomerically pure compounds for agrochemistry, pharmaceuticals, chemical industry, and particularly for the total synthesis of pheromones. Racemic 3-substitued 2-hydroxybutane derivatives were produced in fairly high diastereomeric purities by a variety of chemical approaches, such as epimerization, metal-catalysed asymmetric addition etc. Kinetic resolution of these racemates was achieved by enzyme-catalysed reactions. Two lipases, Candida antarctica lipase B and Pseudomonas cepacia lipase were found to be useful in acylations as well as hydrolyses. In the biotransformations studied, the presence and nature of the second vicinal stereocentre in the chiral secondary alcohols investigated seemed to be important, e.g. in terms of the efficiencies of sequential kinetic resolutions, and altering the selectivities as well. QC 20101020 |
format |
Doctoral or Postdoctoral Thesis |
author |
Liu, Rong |
author_facet |
Liu, Rong |
author_sort |
Liu, Rong |
title |
Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
title_short |
Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
title_full |
Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
title_fullStr |
Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
title_full_unstemmed |
Enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
title_sort |
enzymes as catalysts in synthesis of enantiomerically pure building blocks : secondary alcohols bearing two vicinal stereocenters |
publisher |
KTH, Organisk kemi |
publishDate |
2005 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-424 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
Trita-IOK, 1100-7974 2005:96 http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-424 urn:isbn:91-7178-129-3 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766118897123065856 |