反应详情

A mixture of benzyl bromide (37.4 g) and 4-hydroxy-2,2-dimethylbutanoic acid, monopotassium salt, (3.4 g) in dimethylformamide (35 mL) was stirred at room temperature for 18 hours. The precipitate was filtered off and the filtrate was evaporated. The residue was chromatographed on silica gel eluting with 2:1 dichloromethane:ethyl acetate to give 3.95 g (89%) of 4-hydroxy-2,2-dimethylbutanoic acid phenylmethyl ester as a colorless oil. A sample was evaporatively distilled to give the analytical sample: bp 160°-165° C./0.25 mm; IR (CHCl3) 3595 (OH), 1707 (C=O) and 687 cm-1 (C6H5); NMR (CDCl3) δ 1.23 (s, 6, CH3), 1.85 (t, 2, CH2), 3.67 (t, 2, CH2), 5.11 (s, 2, CH2) and 7.34 (s, 5, Ph); MS m/e 222,91.

1. filtrationThe precipitate was filtered off
2. customthe filtrate was evaporated
3. customThe residue was chromatographed on silica gel eluting with 2:1 dichloromethane