Studies towards dynamic kinetic resolution of 4-hydroxy-2-methylcyclopent-2-en-1-one and its E-O-trityloxime

• Published in: Tetrahedron Vol. 72; no. 32; pp. 4813 - 4820
• Main Authors: Michalak, Karol, Wicha, Jerzy, Wójcik, Jacek
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 11.08.2016; Elsevier
• Subjects: 3-Hydroxyl-cyclopent-2-en-1-one; Acetylation; Antarctica; Candida antarctica; Chemistry; Chemistry, Organic; Derivatives; Dynamic kinetic resolution; Dynamic tests; Dynamics; Physical Sciences; Racemization; Reaction kinetics; Ruthenium chloride cymene dimer; Science & Technology; Shvo's catalyst; 3-Hydroxyl-cyclopent-2-en-1-one; Dynamic kinetic resolution; Ruthenium chloride cymene dimer; Shvo's catalyst; ENZYMATIC RESOLUTION; AMBIENT-TEMPERATURE; TRANSFER HYDROGENATION; ALIPHATIC SECONDARY ALCOHOLS; CATALYTIC RACEMIZATION; CYCLIC ALLYLIC ALCOHOLS; CYCLOPENTADIENYLRUTHENIUM COMPLEXES; RUTHENIUM COMPLEXES; CANDIDA-ANTARCTICA; LIPASE
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2016.06.047

Dynamic kinetic resolution through metal complex induced racemization and Candida antarctica lipase mediated enantioselective acetylation of a model hydroxy-ketone: 4-hydroxy-2-methylcyclopent-2-en-1-one and its selected derivatives, has been studied. Racemization of the hydroxy-ketone was efficiently affected by [RuCl2(cymene)]2 complex–triethylamine while Shvo's catalyst triggered an intramolecular redox process. Kinetic resolution of 4-hydroxy-2-methylcyclopent-2-en-1-one with C. antarctica under conditions compatible with [RuCl2(cymene)]2 racemization failed to reach the efficiency threshold. However, dynamic kinetic resolution of its O-trityloxime using [RuCl2(cymene)]2–triethylamine and C. antarctica lipase–isopropenyl acetate combination, was successfully achieved. [Display omitted]