Chemoenzymatic functionalization of cyclic 1,3-diketones

Date

2004

Author

Fındık, Hamide

Metadata

Show full item record

Item Usage Stats

193
views

0
downloads

Chiral a-hydroxy and a-acetoxy enones are important starting materials in the synthesis of many biologically active materials. In this work, enantiomerically pure ?-hydroxy enone and polyoxo cyclohexenones are synthesized starting from 1,3-cyclohexandione. In the first step, 1,3-cyclohexandione is protected under acid catalyzation and 3-methoxy-2-methyl-2-cyclohexen-1-one is obtained. a'-Acetoxy enone is obtained by Mn(OAc)3 mediated oxidation which is an attractive alternative to other multi-step procedures in the literature. Enzymatic kinetic resolution is applied to the racemic form of this product and enantiomerically pure a'-acetoxy enone and a'-hydroxy enone is obtained. In this stage, for the screening of the reaction many enzymes were tried. Reduction of a'-hydroxy enone furnished enantiopure ?-hydroxy enone.

Subject Keywords

Carbonyl compounds., Chemistry, Organic

URI

http://etd.lib.metu.edu/upload/1116383/index.pdf
https://hdl.handle.net/11511/13905

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Chemoenzymatic synthesis of 4-hydroxy enones Köse, Elif; Demir, Ayhan Sıtkı; Department of Chemistry (2004) Chiral cyclic polyoxo-ketones are important structural units in many natural products, biologically active compouds, such as prostaglandins, didemnenones, sarkomycin, punaglandin, clavulone, etc. In this work, a chemoenzymatic synthesis of both enantiomers of the a̕-acetoxy-a-methyl and ?-hydroxy-a-methyl cyclic enones starting from a-methyl-β-methoxy cyclic enone is described. Manganese (III) acetate-mediated acetoxylation followed by the enzyme-mediated hydrolysis of a̕-acetoxy enone provides acetoxy enon...
Chemoenzymatic functionalization of cyclic 1,2-diketones Biçer, Işıl; Akkaya, Engin Umut; Department of Chemistry (2006) Chiral hydroxylated cyclopentane derivatives are important structural units in many biologically active compounds and are also important synthons for the asymmetric synthesis of natural products. Synthesis of these types of compounds in optically pure form found increased interest in pharmaceutical chemistry. For this purpose 5-acetoxy-3-methyl-2-methoxy-2-cyclopentene-1-one and 5-acetoxy-3-ethyl-2-methoxy-2-cyclopentene-1-one were acetoxylated using manganese (III) acetate at a’ positions. Enzyme catalyzed...
Chemoenzymatic synthesis of chiral hydroxymethyl cycloalkenols Şenocak, Deniz; Demir, Ayhan Sıtkı; Department of Chemistry (2004) Chiral cyclic alkenols with hydroxymethyl functionality are important structural units in many biologically active natural compouds such as prostaglandins, sesquiterpene antiviral agents, pentenomycins, xanthocidin, sarkomycin, etc. 1,3-cycloalkanediones are converted into bicyclic polyoxo derivatives with formaldehyde and trioxane in the presence of Lewis acid. Selective oxidation of the bicyclic compounds by using manganese(III)acetate followed by enzyme-catalyzed kinetic resolution afforded chiral bicycl...
Novel studies on the chemoenzymatic synthesis of polychlorinated bicyclic systems and the synthesis of C2 and C3 symmetric chiral ligands Türkmen, Yunus Emre; Tanyeli, Cihangir; Department of Chemistry (2006) Optically active polychlorinated bicyclic systems are important starting materials for the synthesis of complex target molecules. In the first part of the study, the syntheses of several racemic and meso hexachloronorbornene derivatives were executed successfully, starting from hexachlorocyclopentadiene. The enantio-enriched acetoxymethyl derivative (-)-2 and the hemiester (-)-6 were synthesized in high e.e. values by using several hydrolase type enzymes. The absolute configuration of (-)-2 was determined b...
Oxidative ring opening reactions of a-hydroxy ketones Aybey, Ayşe; Demir, Ayhan Sıtkı; Department of Chemistry (2008) Chiral polyfunctionalized 1,5-dicarbonyl compounds are important synthetic intermediates and starting materials for many biologically active compounds so their synthesis has a great importance in the literature. In the first step, 1,3-cyclohexandione and other b-diketone derivatives are protected under acid catalyzation and their corresponding b-keto enol ether derivatives are obtained. These b-keto enol ethers are then converted to a-acetoxy enones in racemic form by Mn(OAc)3 mediated oxidation. Enzymatic ...

Citation Formats

H. Fındık, “Chemoenzymatic functionalization of cyclic 1,3-diketones,” M.S. - Master of Science, Middle East Technical University, 2004.