3-hydroxy-2-methyl-2H-furan-5-one

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Hydroxy-5-methyl-5H-furan-2-one (15.9 g, 0.14 mol) was dissolved in tert-butanol (13.9 ml, 0.147 mol) with concentrated sulfuric acid (7.8 ml, 0.147 mol) and heated at 40° C. for 4 days. The reaction mixture was allowed to cool and was partitioned between water (75 ml) and diethyl ether (75 ml). The organic layer was separated and dried (Na2SO4), filtered and concentrated under vacuum. Chromatography on silica gel with diethyl ether as eluent gave a crude product which was further purified by chromatography on silica gel with dichloromethane as eluent then triturated with diethyl ether to give 3-tert-butyl-4-hydroxy-5-methyl-5H-furan-2-one (3.1 g) as a white solid. 1H NMR (360 MHz, CDCl3) δ 1.34 (9H, s), 1.46 (3H, d, J=6.7 Hz), 4.69 (1H, q, J=6.7 Hz). to cool was partitioned between water (75 ml) and diethyl ether (75 ml) The organic layer was separated dried (Na2SO4) filtered concentrated under vacuum Chromatography on silica gel with diethyl ether as eluent gave a crude product which was further purified by chromatography on silica gel with dichloromethane as eluent then triturated with diethyl ether

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Hydroxy-5-methyl-5H-furan-2-one (15.9 g, 0.14 mol) was dissolved in tert-butanol (13.9 ml, 0.147 mol) with concentrated sulfuric acid (7.8 ml, 0.147 mol) and heated at 40° C. for 4 days. The reaction mixture was allowed to cool and was partitioned between water (75 ml) and diethyl ether (75 ml). The organic layer was separated and dried (Na2SO4), filtered and concentrated under vacuum. Chromatography on silica gel with diethyl ether as eluent gave a crude product which was further purified by chromatography on silica gel with dichloromethane as eluent then triturated with diethyl ether to give 3-tert-butyl-4-hydroxy-5-methyl-5H-furan-2-one (3.1 g) as a white solid. 1H NMR (360 MHz, CDCl3) δ 1.34 (9H, s), 1.46 (3H, d, J=6.7 Hz), 4.69 (1H, q, J=6.7 Hz). to cool was partitioned between water (75 ml) and diethyl ether (75 ml) The organic layer was separated dried (Na2SO4) filtered concentrated under vacuum Chromatography on silica gel with diethyl ether as eluent gave a crude product which was further purified by chromatography on silica gel with dichloromethane as eluent then triturated with diethyl ether

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Hydroxy-5-methyl-5H-furan-2-one (15.9 g, 0.14 mol) was dissolved in tert-butanol (13.9 ml, 0.147 mol) with concentrated sulfuric acid (7.8 ml, 0.147 mol) and heated at 40° C. for 4 days. The reaction mixture was allowed to cool and was partitioned between water (75 ml) and diethyl ether (75 ml). The organic layer was separated and dried (Na2SO4), filtered and concentrated under vacuum. Chromatography on silica gel with diethyl ether as eluent gave a crude product which was further purified by chromatography on silica gel with dichloromethane as eluent then triturated with diethyl ether to give 3-tert-butyl-4-hydroxy-5-methyl-5H-furan-2-one (3.1 g) as a white solid. 1H NMR (360 MHz, CDCl3) δ 1.34 (9H, s), 1.46 (3H, d, J=6.7 Hz), 4.69 (1H, q, J=6.7 Hz). to cool was partitioned between water (75 ml) and diethyl ether (75 ml) The organic layer was separated dried (Na2SO4) filtered concentrated under vacuum Chromatography on silica gel with diethyl ether as eluent gave a crude product which was further purified by chromatography on silica gel with dichloromethane as eluent then triturated with diethyl ether