p-Toluenesulfonic acid monohydrate → [4-((R)-2-hydroxymethyl-6-oxo-piperidin-1-yl)-but-2-ynyloxy]-acetic acid methyl ester

Participants

Reaction Steps

p-Toluenesulfonic acid hydrate (289 mg, 1.52 mmol) was added to a solution of (4-[(R)-2-(1-ethoxy-ethoxymethyl)-6-oxo-piperidin-1-yl]-but-2-ynyloxy}-acetic acid methyl ester (494 mg, 1.45 mmol) in MeOH (5.0 mL) at rt. After 20 h at rt, the mixture was concentrated in vacuo, treated with saturated aqueous NaHCO3 (20 mL) and extracted with CH2Cl2 (3×20 mL). The combined organic phase was dried (MgSO4), filtered and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (CH2Cl2 →3% MeOH/CH2Cl2, gradient) afforded 100 mg (26%) of [4-((R)-2-hydroxymethyl-6-oxo-piperidin-1-yl)-but-2-ynyloxy]-acetic acid methyl ester.

Provenance & Evidence