Enzymatic kinetic resolution studies of racemic 4-hydroxycyclopent-2-en-1-one using Lipozyme IM®

Enantioselective preparation of (R) and (S)-3-hydroxycyclopentanone by kinetic resolution

“…This is in line with the earlier observation that only cyclopentanol derivatives with large or many substituents give high E value in kinetic resolution [21][22][23][24][25][26][27][28][29][30][31][32][33]. Those with small and few substituents, such as cyclopent-4-ene-1,3-diyl diacetate (80% yield, 20.5% ee) [34], cyclohex-2-en-1-yl acetate [35], 4-hydroxycyclopent-2-en-1-one (E = 11) [36], 4-hydroxy-2-methyl-2-cyclopentenone (60% yield, 60% ee) [37], 3-bromocyclopent-2-enol [38] give less enantiopure products. An exception is the meso compounds [43][44][45][46][47][48][49], however here the stereo differentiation is based on a different principle.…”

“…A general trend observed is that derivatives with large substituents are readily resolved [21][22][23][24][25][26][27][28][29][30][31][32][33], while simple compounds similar to our target molecule tend to give low E values [34][35][36][37][38].…”

Chemistry of 4‐Hydroxy‐2‐cyclopentenone Derivatives

“…Indeed, one convenient large-scale preparation of 4-hydroxy-2-cyclopentenone itself is the acid-catalysed rearrangement of furfuryl alcohol. [12] Each of the two isomeric 4-hydroxy-2-cyclopentenones 35 and 38 were obtained from 2,5-dimethylfuran 33 (Scheme 4). [13] Treatment of this starting material with mCPBA at 0°C produced dienone 34, which underwent an intramolecular aldol reaction when treated with base to give the 4-hydroxy-4-methyl-2-cyclopentenone 35 in 75 % yield.…”

4‐Heterosubstituted Cyclopentenone Antiviral Compounds: Synthesis, Mechanism, and Antiviral Evaluation

“…The kinetic resolution was carried out in organic solvent (anhydrous diisopropyl ether) with vinyl acetate (5 equiv.) in the presence of Lipozyme IM® (10 mol‐%) 17. Oxocyclopentenyl acetate ( S )‐ 10 was obtained in 70 % yield with a good 55 % ee (Scheme ).…”