Sodium hydride → 7-[(R)-2-oxo-6-((E)-3-oxo-oct-1-enyl)-piperidin-1-yl]-hept-5-ynoic acid methyl ester

Participants

Reaction Steps

Sodium hydride (60% dispersion in oil, 8.8 mg, 0.22 mmol) was added to a solution of dimethyl 2-oxoheptylphosphonate (52 mg, 0.23 mmol) in THF (1 mL) at 0° C. After 10 min at 0° C., the solution was allowed to warm to rt. After 1 h at rt, the solution was recooled to 0° C. and 7-((R)-2-formyl-6-oxo-piperidin-1-yl)-hept-5-ynoic acid methyl ester (crude from previous reaction, ˜0.22 mmol) in THF (1 mL) was added via cannula. The reaction was allowed to warm to rt. After 18.5 h at rt, the reaction was quenched with aqueous acetic acid (50%, 5 mL) and extracted with EtOAc (3×10 mL). The combined organic phase was washed with saturated aqueous NaHCO3 (10 mL) and brine (10 mL) then dried (Na2SO4), filtered and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (CH2Cl2→2% MeOH/CH2Cl2, gradient) afforded 68 mg (85%) of 7-[(R)-2-oxo-6-((E)-3-oxo-oct-1-enyl)-piperidin-1-yl]-hept-5-ynoic acid methyl ester.

Provenance & Evidence