Diethyl 2,5-dioxooctahydropentalene-1,3-dicarboxylate → HCID 19907095, compound

Participants

Reaction Conditions

Reaction Steps

10 g of 2,4-bisethoxycarbonylbicyclo[3.3.0]-octane-3,7-dione is dissolved in 40 ml of ethanol and diluted with 0.1-molar phosphate buffer pH 7 to a volume of 1,000 ml. Thereafter, 5 g of α-chymotrypsin from bovine pancreas (activity 1150 U/mg, Chemie Pharmazie Commerz, Hamburg) is added and the mixture shaken on a rotary shaker for 44 hours at 30° C. Then the reaction mixture is extracted three times with methyl isobutyl ketone, the extracts are combined and concentrated to dryness under vacuum. The remaining oily residue (9.4 g) is chromatographed for purification over a silica gel column by means of a solvent gradient of hexane/ethyl acetate. After evaporation of the main fraction, 6.68 g (89.7% of theory) of pure 2-ethoxycarbonylbicyclo[3.3.0]octane-3,7-dione is obtained as a pale, colorless oil which does not crystallize.

Provenance & Evidence