Reaktion #474060

Reaktionsgleichung

2-[(3R)-oxolan-3-yl]ethyl methanesulfonate

2-acetylsulfanyl-2-methyl-propionic acid ethyl ester

sodium methoxide

→

ethyl 2-methyl-2-({2-[(3R)-oxolan-3-yl]ethyl}sulfanyl)propanoate

Ausbeute 29.4%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent is removed under reduced pressure
2. 2
   workup.DISSOLUTIONThe residue is dissolved in ethyl acetate (50 mL)
3. 3
   Waschenwashed with saturated aqueous NaHCO3 solution (2×15 mL) and 1M aqueous HCl solution (2×15 mL)
4. 4
   TrocknenThe organic layer is dried over Na2SO4
5. 5
   Filtrationfiltered
6. 6
   Einengenthe filtrate is concentrated under reduced pressure
7. 7
   SonstigeThe residue is purified twice by column chromatography (silica, eluent: heptanes, ethyl acetate)

Vorschrift

To a solution of 1.13 g (5.94 mmol) of 2-acetylsulfanyl-2-methyl-propionic acid ethyl ester in ethanol (20 mL, degassed) are added 1.28 g (23.7 mmol) of sodium methoxide, followed by 1.13 g (5.94 mmol) of 2-[(3R)-oxolan-3-yl]ethyl methanesulfonate under nitrogen atmosphere. The reaction is heated to 80° C. for 16 h. The solvent is removed under reduced pressure. The residue is dissolved in ethyl acetate (50 mL) and washed with saturated aqueous NaHCO3 solution (2×15 mL) and 1M aqueous HCl solution (2×15 mL). The organic layer is dried over Na2SO4, filtered and the filtrate is concentrated under reduced pressure. The residue is purified twice by column chromatography (silica, eluent: heptanes, ethyl acetate) to afford 0.43 g of ethyl 2-methyl-2-({2-[(3R)-oxolan-3-yl]ethyl}sulfanyl)propanoate (UV purity: 70%). Yield: 21%, m/z 247 [M+H]; 1H NMR (250 MHz, CHLOROFORM-d) δ ppm 1.29 (3 H, t, J=7.08 Hz), 1.43-1.81 (9H, m), 1.95-2.16 (1H, m), 2.20-2.35 (1H, m), 2.53-2.67 (2 H, m), 3.34 (1H, dd, J=8.38, 7.16 Hz), 3.66-3.98 (3H, m), 4.17 (2H, q, J=7.06 Hz)

Quelle