Acetic Acid → (R)-3-(3-methoxybenzyl)-4-oxocyclopent-2-enyl acetate

4-Hydroxy-2-(3-methoxybenzyl)cyclopent-2-enone (9 g, 41.26 mmol) was dissolved in isobutyl methyl ketone (90 mL), and vinyl acetate (8.4 g, 97.57 mmol) and Lipase derived from Pseudomonas cepacia (0.9 g) were added to the solution, and the mixture was stirred at room temperature overnight. The reaction mixture was filtered to remove the Lipase and the filtrate was evaporated. The resulting residue was dissolved in PhCH3 (150 ml), and triphenylphosphine (6.5 g; 24.78 mmol) and AcOH (1.61 g, 26.81 mmol) were added to the solution. Then diisopropylazodicarboxylate (5 g, 24.72 mmol) 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 purified by chromatography on a silica gel column using hexane-EtOAc as eluent to give the (R)-3-(3-methoxybenzyl)-4-oxocyclopent-2-enyl acetate as yellow oil: 10 g (yield: 93%, 95% ee by HPLC using a chiral column)

1. additionwere added to the solution
2. filtrationThe reaction mixture was filtered
3. customto remove the Lipase
4. customthe filtrate was evaporated
5. dissolutionThe resulting residue was dissolved in PhCH3 (150 ml)
6. filtrationthe reaction mixture was filtered
7. customto remove the precipitate
8. customthe filtrate was evaporated
9. customThe residue was purified by chromatography on a silica gel column

ORD-Eintrag

ord-b5d27e2556a84897bdcb1111261a2766

Quelldatensatz

uspto-grants-2013_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08350090B1