Water → (S)-5-(2-Hydroxyethyl)-2,2-dimethyl-1,3-dioxolan-4-one p-toluenesulfonate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Dried (S)-5-(2-hydroxyethyl)-2,2-dimethyl-1,3-dioxolane-4-one (9.0 g, 59.2 mmol) was dissolved in 100 mL of anhydrous pyridine under argon and cooled to -4° C. To this solution maintained at approximately 0° C. was added dropwise 11.3 g (59.22 mmol) of p-toluenesulfonyl chloride dissolved in 100 mL of pyridine. Following addition, the mixture was placed in the refrigerator (0°-4° C.) overnight. Water (150 mL) was added, and the aqueous mixture extracted with 4×200 mL of ether. The ether layers were combined, washed with 3 ×150 mL of water, 3×150 mL of saturated copper sulfate solution (until no dark blue color remained), 2×100 mL of water, 3×150 mL of brine, dried (Na2SO4), filtered, and evaporated under reduced pressure. The crude tosylate was purified by column chromatography using ethyl acetate:hexanes (1:1) to provide the title compound, 16.7 g (95%) as white solid: mp 48°-49° C.; α!D25 -3.7° (c=0.3, CH3OH); IR (KBr, cm-1) 2989, 1785, 1390, 1357, 1278 1H NMR (CDCl3) δ 7.80 (d, J=8.3 Hz, 2H), 7.36 (d, J=8.3 Hz, 2H), 4.43 (dd, J=4.4, 8.1 Hz, 1H), 4.27-4.14 (m, 2H), 2.46 (s, 3H), 2.3-2.17 (m, 1H), 2.09-1.92 (m, 1H), 1.58 (s, 3H), 1.51 (s, 3H); HRMS calculated for C14H18O6S (M+), 314.0824, found 314.0817.

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