Potassium Carbonate → HCID 54445672, compound

Participants

Reaction Steps

To a solution of 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-hydroxypropionic acid (27.9 g, 87.9 mmol) in dimethylformamide (280 mL) at 0° C., was added potassium carbonate (72.9 g, 527 mmol) and a solution of 3,4-methylenedioxybenzyl chloride ((60 g, 170.8 mmol, 50% (w/w)) in methylene chloride. After 2 h, lithium iodide (5.88 g, 44 mmol) was added and the reaction mixture was warmed to rt. over 2 h. After 6 h, the reaction mixture was partitioned between ethyl acetate (600 mL) and water (250 mL). The organic layer was separated, dried over magnesium sulfate and concentrated in vacuo. The crude residue was chromatographed (300 g SiO2, 15% ethyl acetate-hexanes) to afford 2(R)-(4-methoxy-2,3,6-trimethylbenzenesulfonylamino)-3-hydroxypropionic acid 3,4-methylenedioxybenzyl ester (38.4 g) which was taken directly into the next reaction without further purification.

Provenance & Evidence