Details

Autor(en) / Beteiligte

• Hameršak, Zdenko
• Ljubović, Edina
• Merćep, Mladen
• Mesić, Milan
• Šunjić, Vitomir

Titel

Chemoenzymatic Synthesis of All Four Cytoxazone Stereoisomers

Ist Teil von

• Synthesis (Stuttgart), 2001, Vol.2001 (13), p.1989-1992

Erscheinungsjahr

2001

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• 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.