Pyridine → (3aS)-Tetrahydro-1H,3H-1lambda~6~-pyrrolo[1,2-c][1,2,3]oxathiazole-1,1-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of (S)-pyrrolidin-2-yl-methanol (25.0 g, 0.247 mol) in dichloromethane (165 ml) was added pyridine (41 ml, 0.508 mol). The solution was stirred while being cooled in dry ice/acetone bath until the temperature of the mixture was below −68° C. Sulfuryl chloride (20 ml, 0.247 mol) was added over 45 minutes while maintaining the reaction temperature below −60° C. The reaction temperature was allowed to warm to −40° C. and held for two hours while pyridine hydrochloride precipitates. The reaction mixture was allowed to warm to ambient temperature and was stirred for an additional 50 minutes. The reaction mixture was poured onto ice water (300 ml). The organic layer was separated and the aqueous phase was extracted with dichloromethane (150 ml). The combined organic layers are washed with 1N HCl (100 ml), water (100 ml) and saturated NaCl (100 ml) and then dried over Na2SO4. After evaporation of the solvent, the crude product (32.4 g in the form of a orange resin) was purified by flash chromatography over silica gel (eluent:cyclohexane/ethyl acetate 6:4) to afford 29.3 g (72.7% of theory) of (S)-tetrahydro-pyrrolo[1,2-c][1,2,3]oxathiazole 1,1-dioxide as a white solid m.p. 46-50° C.

Provenance & Evidence