Dicyclohexylcarbodiimide → HCID 131714247, compound

Participants

Reaction Steps

To a solution of (5S)-5-benzoyloxy-2-methyl-4-oxo-6-phenylhexanoic acid (740 mg., 2.17 mmole), L-proline, phenylmethyl ester, hydrochloride (525 mg., 2.17 mmole), 1-hydroxybenzotriazole hydrate (300 mg., 2.21 mmole), and diisopropylethylamine (0.45 ml., 2.6 mmole) in anhydrous tetrahydrofuran (8 ml.) at 0° under argon is added dropwise a solution of dicyclohexylcarbodiimide (457 mg., 2.21 mmole) in tetrahydrofuran (1.5 ml.). The resulting mixture is stirred at 0° for one hour and then warmed to room temperature. After stirring for 16 hours, the mixture is diluted with ether and washed with water, 1N hydrochloric acid (twice), 1N sodium bicarbonate, and brine. After drying (MgSO4), the solvent is removed at reduced pressure to give the desired product as a mixture of diastereomers. Flash chromatography [Whatman silica gel LPS-1; solvent, hexane:dichloromethane:ethyl acetate (6:2:2)] gives 460 mg. of 1-[(5S,2R)-5-(benzoyloxy)-2-methyl-1,4-dioxo-6-phenylhexyl]-L-proline, phenylmethyl ester; Rf =0.45 [silica gel, dichloromethane:ethyl acetate:hexane (4:3:3)].

Provenance & Evidence