Dimethyl Sulfoxide → 3,4-Di-O-n-propyl-6-deoxy-L-glucal

Participants

Reaction Steps

n-Propyl iodide (39 mL, 0.40 mol), 3,4-di-O-acetyl-6-deoxy-L-glucal (4.28 g, 0.20 mol), 50% aqueous NaOH (43 mL, 0.81 mol) and DMSO (11.4 mL, 0.16 mol) were added sequentially to a 300-mL round-bottom, three-neck flask equipped with an overhead stirrer. Stirring was begun and tetrabutylammonium hydrogen sulfate (2.04 g, 0.006 mol) added in a single portion. The mixture was stirred for 17 h. at room temperature. The mixture was partitioned between water and pentane. The aqueous layer was extracted with additional pentane. The combined organic layers were successively washed with water (three times), dilute aqueous sodium thiosulfate, dilute sodium bicarbonate and brine. The solvent was removed under reduced pressure (20 Torr followed by 0.1 Torr) to yield a pale yellow oil (4.0 g, 94%) that could be used without further purification. 1H NMR d 6.31 (dd, J=6.1, 1.4, 1 H), 4.78 (dd, J=6.1, 2.4, 1 H), 1.60 (m, 4 H), 1.37 (d, J=6.4, 3 H), 0.93 (t, J=6.3, 3 H), 0.94 (t, J=6.3, 3 H).

Provenance & Evidence