3-benzyl-[1,2]oxathiolane 2,2-dioxide

Synthesis

The general procedure for the synthesis of 3-benzyl-1,2-oxathiolane 2,2-dioxide from benzyl bromide was as follows: a 1,3-propanesulfonolactone solution of 4-{[(1S)-1-(4-fluorophenyl)ethyl]amino}-1-phenyl-2-butanesulfonic acid up to -78°C (5.0 g, 41 mmol) was prepared in anhydrous THF (150 mL) by the addition of butyl lithium ( 2.5 M hexane solution, 18 mL, 41 mmol). The reaction mixture was stirred at -78 °C for 0.5 h, followed by the slow addition of benzyl bromide (4.9 mL, 41 mmol) via syringe pump over 0.5 h. The reaction mixture was stirred for 0.5 h at -78 °C. Stirring of the reaction mixture was continued at -78 °C for 2 hours. Afterwards, the reaction mixture was warmed to 0 °C and water (100 mL) was slowly added to quench the reaction. The organic layer was separated and the aqueous phase was extracted with EtOAc (2 x 25 mL). The organic phases were combined, dried with anhydrous Na2SO4, filtered and concentrated under reduced pressure. Purification by fast chromatography (unfolding agent ratio 80% Hex/EtOAc, Rf = 0.14) afforded the target product 1-benzyl-1,3-propanesulfonic acid lactone (5.23 g, 60% yield).

References

[1] Patent: US2006/183800, 2006, A1. Location in patent: Page/Page column 69