Lipase-catalyzed irreversible transesterification using enol esters: resolution of prostaglandin synthons 4-hydroxy-2-alkyl-2-cyclopentenones and inversion of the 4S enantiomer to the 4R enantiomer

Abstract

Springer-Verlag: Berlin, 1989; p 148). For the use of enol esters in lipase reaction with alcohols, see: Degueil-Cashing, M.; Jeso, B. D.; Drouillard, S.; Mailard, B. Tetrahedron Lett. 1987, 28, 953 (no enantioselective transformation was reported). Laumen, K.; Breitgoff, D.; Schneider, M. P. J . Chem. Soc.,

Chemistry of 4‐Hydroxy‐2‐cyclopentenone Derivatives

“…Nevertheless, this strategy has been used to deracemise a panel of (Ϯ)-2-substituted 4-hydroxy-2-cyclopentenones 114 via an irreversible lipase-catalysed acylation reaction (Scheme 19). [42] Porcine pancreas lipase exhibited a high selectivity for the transformation of alcohols with the Rconfiguration. Thus both the unreacted alcohols (S)-114 (35-48 % yield) and the acetylated products (R)-115 (35-46 % yield) were isolated in highly enantiomerically enriched form, with the ee falling within the range 92-99 %.…”

Chemoenzymatic Approach to Optically Active 4‐Hydroxy‐5‐alkylcyclopent‐2‐en‐1‐one Derivatives: An Application of a Combined Circular Dichroism Spectroscopy and DFT Calculations to Assignment of Absolute Configuration

“…). Several representatives of this group of compounds have been successfully resolved using various lipases and acylating reagents . However, to the best of our knowledge no reports on the preparation of closely related optically active 4‐hydroxy‐5‐alkylcyclopent‐2‐en‐1‐ones ( 2 , Fig.…”

Effective Stereoselective Total Synthesis of 16,16-Dimethyl Prostaglandin E2

“…The chiral building block 2 has been described by Babiak et al [9] , but a synthesis of optically pure 3, suitable for a large scale process, was required. The classical methods using racemate cleavage has the great disadvantage that only one enantiomer is of use and the antipode is often discarded.…”