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Title

Α) Σύνθεση α,α-διχλωρο-β-κέτο εστέρων και μελέτη ενζυμικής αναγωγής τους Β) Σύνθεση και φωτοοξείδωση φαίνυλοκυκλοπεντενίου

Alternative Title

Α) Synthesis and enzymatic reduction of α,α-dichloro-β-keto esters Β) Synthesis and photooxidation of phenylcyclopente

Author

Κεφαλογιάννη, Μαρία

Thesis advisor

Σμόνου, Ιουλία

Abstract

The subject of the present thesis was the enantioselectivity study of the enzymatic reduction of α,α-dichloro-β-keto esters with ketoreductases in order to form compounds of high added value which can be used as intermediates in natural products synthesis. The photooxidation of an alkene substrate was also studied using singlet oxygen, ¹Ο₂, as well as the photooxidation test of the produced allylic alcohol through an anthraquinone derivative in order to develop a synthetic route that combines Biocatalysis and Photocatalysis. In the first part, the enantioselective reduction of α,α-dichloro-β-keto esters using the NADPH-dependent ketoreductase, KRED 101, to form the corresponding α,α-dichloroβ-hydroxy esters is presented. More specifically, 2,2-dichloro-3-cyclohexyl-3- oxopropanoate methyl ester was synthesized as the substrate, its enzymatic reduction was studied and the absolute configuration of the reduced product was determined using MPA-esters. The reduction product, methyl 2,2-dichloro-3-cyclohexyl-3-hydroxypropanoate, was formed in excellent enantiomeric excess >99 % ee and in fairly good yield. The enantioselective reduction of α,α-dichloro-β-keto ester substrates was then studied in a four times larger scale and the reduction products were formed with excellent enantioselectivity, in very good yields and. In the second part, the synthesis of phenyl-cyclopentene and the study of its photooxidation using singlet oxygen, ¹Ο₂ is presented. The photooxidation of the allylic alcohol, 2-phenylcyclopent-2-en-1-ol, to form the corresponding enone was also studied using the commercially available water-soluble sodium anthraquinone sulfonate (SAS). The results of this specific photooxidation were not satisfactory.

Language

Greek

Subject

Anthraquinone

Enantioselective bioreduction

Ketoreductases

a,a-dichloro-b-keto esters

Ανθρακινόνη

Εναντιοεκλεκτική βιοαναγωγή

Κετορεδουκτάσες

Μοριακό οξυγόνο απλής κατάστασης

α-διχλωρο-β-κέτο εστέρες