反应详情

温度

-80 °C

A mixture of L-Lactic acid (106 g of 85% in H2O), pivalaldehyde (220 mL), p-toluene sulfonic acid mono hydrate (2.0 g) and H2SO4 conc. (8 drops) in pentane (800 mL) was refluxed with azeotropic removal of the water formed using a Dean-Stark trap. The supernatant was decanted, washed with water, dried over MgSO4 and concentrated. The resulting residue was dissolved in hexane (800 mL) and cooled to -80° C. for 20 h. Crystals were collected by filtration in a cold room (5° C.) and washed with cold hexane (-78° C.). The crystals were dissolved in Et2O, dried over MgSO4 and concentred to give the title compound as a colorless oil. 1H NMR(CD3COCD3): δ0.95 (9H, s), 1.38 (3H,d), 4.47 (1H, m), 5.24 (1H, s).

1. customformed
2. customThe supernatant was decanted
3. washwashed with water
4. dry with materialdried over MgSO4
5. concentrationconcentrated
6. dissolutionThe resulting residue was dissolved in hexane (800 mL)
7. filtrationCrystals were collected by filtration in a cold room (5° C.)
8. washwashed with cold hexane (-78° C.)
9. dissolutionThe crystals were dissolved in Et2O
10. dry with materialdried over MgSO4