Chemoenzymatic Synthesis of All Four Cytoxazone Stereoisomers
- 1 January 2001
- journal article
- research article
- Published by Georg Thieme Verlag KG in Synthesis
- Vol. 2001 (13) , 1989-1992
- https://doi.org/10.1055/s-2001-17711
Abstract
Racemic cytoxazone (±-5) was synthesized starting from easily available glycidic ester (±)-1 by nucleophilic epoxide ring opening, followed by 2-oxazolidinone ring construction and calcium chloride/sodium borohydride reduction of the intermediary ester (±)-4. Kinetic resolution of (±)-5 performed by acetylation with vinyl acetate catalyzed by Penicillium camemberti lipase (PcamL) afforded, on hydrolysis of acetate (-)-6, cytoxazone (-)-5 in 33% overall yield and 88.2% enantiomeric excess (ee), and its enantiomer (+)-5 (38% yield, 89.3% ee). Base-catalyzed epimerization of intermediary (±)-4 to (±)-7, and reduction and kinetic resolution with Candida antarctica lipase (CAL) led to epi-cytoxazones (-)-8 and (+)-8.Keywords
This publication has 0 references indexed in Scilit: