反应详情

A solution of (S)-(+)-2,2-dimethyl-5-oxo-1,3-dioxolane-4-acetic acid (2.08 g, 11.9 mmol), which was derived from L-malic acid by means known in the art, in dry dichloromethane (20 ml) was treated with triethylamine (1.83 ml, 13.1 mmol) followed by a solution of t-butylchlorodiphenylsilane (3.44 g, 12.5 mmol) in dichloromethane (5 ml) added dropwise over 5 minutes. After 3 hours at 22° C., the reaction mixture was diluted with toluene (250 ml) washed with water, saturated sodium bicarbonate, brine and dried over magnesium sulfate. Evaporation of the solvent under reduced pressure and chromatography of the residue on silica gel (4×12 cm) using a mixture of toluene and ethyl acetate (0-2%) as eluent gave 4.90 g (99%) of the title material as a clear oil. 1H NMR (400 MHz, CDCl3) δ: 1.13 (s, 9), 1.58 (s, 3), 3.05 (m, 2), 4.79 (dd, 1, J=4, 7), 7.4-7.8 (m, 10).

1. additionadded dropwise over 5 minutes
2. washwashed with water, saturated sodium bicarbonate, brine
3. dry with materialdried over magnesium sulfate
4. customEvaporation of the solvent under reduced pressure and chromatography of the residue on silica gel (4×12 cm)
5. additiona mixture of toluene and ethyl acetate (0-2%) as eluent