Acetic Anhydride → HCID 68688605, compound

Participants

Reaction Conditions

Reaction Steps

The acetonitrile solution (50 mL) of 5,6-dihydro-4H-cyclopenta[b]furan-2-carbaldehyde (1.33 g) was added to the dry acetonitrile (101 mL) solution of anhydrous MgBr2 (cont. 98%) (5.52 g) under a nitrogen atmosphere at room temperature. The dry THF solution (151 mL) of (5R,6S)-6-bromo-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid 4-nitrobenzyl ester (cont. 96.5%) (3.91 g) was added to the mixture, cooled to −20° C., and Et3N (cont. 99%) (8.28 mL) was added in one portion. The reaction vessel was covered with foil to exclude light. The reaction mixture was stirred for 2 h at −20° C. and treated with acetic anhydride (cont. 97%) (4.13 mL) and DMAP (cont. 99%) (121 mg) in one portion. The reaction mixture was warmed to 0° C. and stirred for 16 h at 0° C. The mixture was diluted with ethyl acetate and washed with 5% aqueous solution of citric acid, saturated sodium hydrogen carbonate and brine. The organic layer was dried (MgSO4) then filtered. The filtrate was concentrated under reduced pressure. The residue was purified with a silica-gel column chromatography (n-hexane:AcOEt=4:1–3:1) to give the titled compound as a brown amorphous solid (3.34 g, 61%).

Provenance & Evidence