Methanesulfonic Acid → (1R)-1-{(4S)-2-[5-(3-{[(2S)-1-Methoxypropan-2-yl]oxy}-5-[(tripropan-2-ylsilyl)oxy]phenyl)-1H-pyrrol-2-yl]-4,5-dihydro-1,3-oxazol-4-yl}ethanol

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Reaction Steps

N-[(2S,3R)-1,3-Dihydroxybutan-2-yl]-5-(3-{[(2S)-1-methoxypropan-2-yl]oxy}-5-[(tripropan-2-ylsilyl)oxy]phenyl)-1H-pyrrole-2-carboxamide (1.70 g, 3.18 mmol) synthesized in Example (114a) was dissolved in tetrahydrofuran (20 mL), and anhydrous methanesulfonic acid (0.78 g, 4.48 mmol) and triethylamine (1.50 mL, 10.76 mmol) were added at 0° C., followed by stirring at the same temperature for 1.5 hours under nitrogen atmosphere, followed by stirring at 50° C. overnight. To the reaction solution, a saturated aqueous ammonium chloride solution (50 mL) was added, and extraction was carried out with methylene chloride (50 mL). The organic layer was washed with saturated brine, and subsequently dried over anhydrous magnesium sulfate. The solvent was distilled off under reduced pressure, and the resulting residue was purified using silica gel column chromatography (elution solvent: methanol/methylene chloride=2%-4%) to afford the desired compound (1.30 g, yield 79%) as a white foam.

Provenance & Evidence