Lithium borohydride → HCID 66790672, compound

Participants

Reaction Steps

Lithium borohydride (2.0 M in THF, 0.25 mL, 0.50 mmol) was added slowly to a solution of (R)-1-[2-(3-methoxycarbonyl-propylsulfanyl)-ethyl]-6-oxo-piperidine-2-carboxylic acid ethyl ester (160 mg, 0.48 mmol) in CH2Cl2 (1.5 mL) at −40° C. After 4.5 h at −40° C., the reaction was quenched by addition of a few drops of aqueous HCl (6 N) until gas evolution ceased. Solid NaHCO3 was added and the reaction mixture was filtered and concentrated in vacuo. Purification of the residue by flash column chromatography on silica gel (CH2Cl2→2% MeOH/CH2Cl2, gradient) afforded 33 mg (˜23%) of an inseparable mixture of desired product 4-[2-((R)-2-hydroxymethyl-6-oxo-piperidin-1-yl)-ethylsulfanyl]-butyric acid methyl ester and undesired product (R)-1-[2-(4-hydroxybutylsulfanyl)-ethyl]-6-oxo-piperidine-2-carboxylic acid ethyl ester.

Provenance & Evidence