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

Participants

Reaction Steps

p-Toluenesulfonic acid hydrate (620 mg, 3.26 mmol) was added to a solution of {(Z)-4-[(R)-2-(1-ethoxyethoxymethyl)-6-oxo-piperidin-1-yl]-but-2-enyloxy}-acetic acid ethyl ester (1.10 g, 3.08 mmol) in MeOH (10 mL). After 17 h at rt, the reaction was quenched with saturated aqueous NaHCO3 (20 mL) and the mixture was extracted with CH2Cl2 (3×30 mL). The combined organic phase was dried (Na2SO4), filtered and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (40% EtOAc/CH2Cl2→60% EtOAc/CH2Cl2, gradient, then 7% MeOH/CH2Cl2) afforded 538 mg (64%) of [(Z)-4((R)-2-hydroxymethyl-6-oxo-piperidin-1-yl)-but-2-enyloxy]-acetic acid methyl ester.

Provenance & Evidence