反应详情

4-Hydroxy-2-(3-Benzyloxybenzyl)cyclopent-2-enone (2.1 kg, 7.14 mol) was dissolved in isobutyl methyl ketone (21 L), and vinyl acetate (4.2 kg, 51.16 mol) and Lipase derived from Pseudomonas cepacia (210 g) was added to the solution, and the mixture was stirred at room temperature for 1 day. The reaction mixture was filtered to remove Lipase and the filtrate was evaporated. The resulting residue was dissolved in PhCH3 (20 L), and triphenylphosphine (625 g, 2.38 mol) and AcOH (145 g, 2.41 mol) was added to the solution. Then diisopropylazodicarboxylate (413 g, 2.04 mol) was added to the mixture at 5° C. After the reaction was completed, the reaction mixture was filtered to remove the precipitate and the filtrate was evaporated. The residue was dissolved in EtOAc (5 L) and hexane (5 L) was added. The mixture was stirred at room t temperature overnight. The mixture was filtered to remove the precipitate and the filtrate was evaporated. The residue was purified by chromatography on a silica gel column using hexane-EtOAc as eluent to give the (R)-3-(3-benzyloxybenzyl)-4-oxocyclopent-2-enyl acetate as yellow oil: 1.8 kg (yield: 75%, 97% ee by HPLC using a chiral column)

1. additionwas added to the solution
2. filtrationThe reaction mixture was filtered
3. customto remove Lipase
4. customthe filtrate was evaporated
5. dissolutionThe resulting residue was dissolved in PhCH3 (20 L)
6. filtrationthe reaction mixture was filtered
7. customto remove the precipitate
8. customthe filtrate was evaporated
9. dissolutionThe residue was dissolved in EtOAc (5 L)
10. additionhexane (5 L) was added
11. stirringThe mixture was stirred at room t temperature overnight
12. filtrationThe mixture was filtered
13. customto remove the precipitate
14. customthe filtrate was evaporated
15. customThe residue was purified by chromatography on a silica gel column