反应详情

温度

-10 °C

A drop of p-toluene sulfonic acid was added at -15° C. to a solution of 1.42 g of 5.6-epoxy-4,4-dimethyl-tetrahydro-pyr-2-one melting at ≃22° C., 14 ml of methylene chloride and 320 mg of methanol and the mixture was stirred for 31/2 hours at -10° C. 0.4 ml of methanol were added and the mixture was stirred at -10° C. for 16 hours. 40.4 ml of methanol and a little p-toluene sulfonic acid were added and the mixture was stirred for 48 hours while letting the temperature rise to room temperature. The mixture was decanted and the liquid phase was washed with aqueous saturated sodium bicarbonate solution, then with water, was dried and evaporated to dryness under reduced pressure. The 1.45 g of residue was chromatographed over silica and was eluted with a 1-1 mixture of hexane-ethyl acetate to obtain 1.42 g of dl 6-methoxy-5-hydroxy-4,4-dimethyl-tetrahydro-pyr-2-one melting at 72° C. and having a Rf=0.20.

1. stirringthe mixture was stirred for 48 hours
2. customto room temperature
3. customThe mixture was decanted
4. washthe liquid phase was washed with aqueous saturated sodium bicarbonate solution
5. dry with materialwith water, was dried
6. customevaporated to dryness under reduced pressure
7. customThe 1.45 g of residue was chromatographed over silica
8. washwas eluted with a 1-1 mixture of hexane-ethyl acetate