Cyclobutanone → HCID 69053186, compound

Participants

Reaction Steps

To a solution of 3-acetyl-2,6-diethyl-4-hydroxyphenyl acetate (4.0 g) and cyclobutanone (1.23 g) in toluene (150 mL) was added pyrrolidine (568 mg). The solution was left at room temperature for 16 hours, refluxed for two hours, and then a Dean-Stark was used to remove the water. After evaporation, the residue was dissolved in methanol and a lithium hydroxide solution (10%) was added until the solution reached a pH value greater than 9. The solution was stirred at room temperature for 2 hours and then neutralized to pH 7 using diluted hydrochloric acid. Work up and chromatography (silica gel, hexane-ethyl acetate 2% to 8%) gave 1.8 g of 5,7-diethyl-6-hydroxyspiro[chroman-2,1′-cyclobutan]-4-one. 1H-NMR (300 MHz, CDCl3) δ=6.67 (s, 1H), 5.14 (s, 1H), 4.01 (s, 3H), 3.11 (q, J=7.4 Hz, 2H), 2.84 (s, 2H), 2.65 (q, J=7.4 Hz, 2H), 2.30-1.65 (m, 6H), 1.30-1.10 (m, 6H) ppm. 13C-NMR (75 MHz, CDCl3) δ=194.3, 155.0, 146.0, 139.9, 130.6, 117.0, 115.8, 79.8, 47.7, 33.0, 23.8, 19.8, 13.9, 13.2, 12.1 ppm.

Provenance & Evidence