3-bromocyclobutan-1-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3-bromocyclobutanone (5.90 g, 39.6 mmol), 1,2-ethanediol (8.6 mL, 158 mmol, 4 eq.) and PPTS (1.90 g, 7.92 mmol) in benzene (40 mL) was heated to reflux using Dean-Stark assembly. After 12 h, the reaction mixture was allowed to cool and washed with water (2×30 mL). The organic phase was dried (Na2SO4) and concentrated. The residue was purified using column chromatography (ethyl acetate/hexanes 1:5) to give the title compound (51% yield starting from 3-oxocyclobutanecarboxylic acid). 1H NMR (300 MHz, CDCl3): δ=2.77-2.82 (m, 4H), 2.95-3.00 (m, 4H), 4.19-4.23 (m, 1H). was heated to reflux to cool washed with water (2×30 mL) The organic phase was dried (Na2SO4) concentrated The residue was purified