Dicyclohexylcarbodiimide → HCID 86675669, compound

Participants

Reaction Steps

To a stirred solution of (R)-2-tert-butoxycarbonylamino-3-methyl-butyric acid (6.3 g, 29.1 mmol) in DMF (40 ml) was added N,N′-dicyclohexylcarbodiimide (6.0 g, 29.1 mmol). After stirring for 30 min at room temperature, reaction mixture was cooled to 0° C., added a solution of {(2R,3R,4R,5S,6S)-3,4,5-tris-benzyloxy-6-[3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-4-ethyl-phenyl]-tetrahydro-pyran-2-yl}-methanol (4.0 g, 5.8 mmol) in DMF (20 ml) followed by DMAP (360 mg, 2.9 mmol) and stirred at ambient temperature for overnight. Reaction was quenched by the addition of water (150 ml) and extracted with ethyl acetate (2×80 ml). Combined organic layers were washed with water (100 ml), brine (100 ml), dried over sodium sulfate, concentrated and purified by silica gel column chromatography to give 4.5 g of (R)-2-tert-butoxycarbonylamino-3-methyl-butyric acid (2R,3R,4R,5S,65)-3,4,5-tris-benzyloxy-6-[3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-4-ethyl-phenyl]-tetrahydro-pyran-2-ylmethyl ester as a colorless oil.

Provenance & Evidence