反应详情

Sodium hydroxide (4.84 g, 121 mmol, 1.1 eq.) dissolved in 10 ml distilled water was added to 100 ml methanol containing 2-hydroxymethyl-3-hydroxy-6-methyl-pyran-4(1H)-one (17.2 g, 110 mmol, 1 eq.) and heated to reflux. Benzyl bromide (20.7 g, 121 mmol, 1 eq.) was added dropwise over 30 minutes and then refluxed overnight. The reaction mixture was concentrated in vacuo, the residue taken up into 300 ml dichloromethane and the inorganic salts filtered off. The dichloromethane layer was washed with 2×100 ml 5% w/v sodium hydroxide solution, 100 ml water, dried (Na2SO4), and concentrated in vacuo to yield the crude product as a yellow crystalline solid. Recrystallisation from CH2Cl2/Pet. ether 40/60 afforded the title product in 80% yield (21.6 g) as a white crystalline solid. m.p. 115-116° C. [lit. 114-116° C. Tilbrook (1995)].

1. distillationdistilled water
2. additionwas added to 100 ml methanol
3. temperatureheated to reflux
4. temperaturerefluxed overnight
5. concentrationThe reaction mixture was concentrated in vacuo
6. filtrationthe inorganic salts filtered off
7. washThe dichloromethane layer was washed with 2×100 ml 5%
8. dry with materialdried (Na2SO4)
9. concentrationconcentrated in vacuo
10. customto yield the crude product as a yellow crystalline solid
11. customRecrystallisation from CH2Cl2/Pet. ether 40/60