Chemoenzymatic functionalization of cyclic 1,2-diketones

Biçer, Işıl
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 enantioselective hydrolysis of hydrolyzed acetoxy derivatives gives the corresponding hydroxylated diketones in optically pure form.


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...
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 ...
Chemoenzymatic functionalization of cyclic 1,3-diketones
Fındık, Hamide; Demir, Ayhan Sıtkı; Department of Chemistry (2004)
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 procedure...
Synthesis of heterocyclic amine substituted novel 1,4-Aminoalcohols and applications in various asymmetric transformations
Keskin, Eda; Tanyeli, Cihangir; Department of Chemistry (2007)
Aminoalcohols are very important compounds used in various asymmetric transformations as chiral ligands or chiral auxiliaries. In this thesis, four novel heterocyclic amine substituted chiral 1,4-aminoalcohols were synthesized. In the synthetic strategy, amide esters were synthesized from (2S, 3R)-3-methoxycarbonylbicyclo[2.2.1]hept-5-ene-2-carboxylic acid by DCC coupling method. Subsequent reduction of these amide esters lead to target 1,4-aminoalcohols. The activities of these novel chiral 1,4-aminoalcoho...
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...
Citation Formats
I. Biçer, “Chemoenzymatic functionalization of cyclic 1,2-diketones,” M.S. - Master of Science, Middle East Technical University, 2006.