反应详情

温度

60 °C

The acetate compound prepared in B (ii) (55 g, GC purity 91%, 0.172 moles) was added over 45 minutes to 98% H2SO4 (50 ml) at 25°-60° C. (exotherm). After stirring for a further 30 minutes at 60° C., water (50 ml) containing acetic acid (10 ml) was cautiously added dropwise and the mixture heated at 100° C. for 3 hours. Petrol (60/80 b.p., 100 ml) was added and the mixture basified to pH 9 with 35% aqueous ammonia (150 ml). Separation of the organic layer, drying (MgSO4) and solvent flash gave the desired product (22.6 g, GC purity 92%, yield 69%). NMR analysis using chiral solvating agent [(-)-2,2,2-trifluoro-1-(9-anthryl)ethanol] showed a 70/30 mixture of enantiomers in favour of the (-)-isomer.

1. additionwas cautiously added dropwise
2. temperaturethe mixture heated at 100° C. for 3 hours
3. customSeparation of the organic layer
4. dry with materialdrying (MgSO4) and solvent flash