2-Pyridone → (2r)-2-benzyl-n-((1S)-2,2-dimethyl-1-methylcarbamoyl-propyl)-2,4-dihydroxy-butyramide

Participants

Reaction Conditions

Reaction Steps

3-Benzyl-3-hydroxy-dihydro-furan-2-one (21c) (0.961 g, 5.00 mmol), H-tLeu-NHMe (1.80 g, 12.5 mmol) and 2-pyridone (0.476 g, 5.0 mmol) was suspended in 10 mL 1,2-dichloroethane in a reaction tube. The vessel was sealed with a screw cap and heated in a metal heating block at 80° C. for 24 h. The solvent was evaporated and the residue was re-dissolved in the least amount of 25% acetonitrile in water and the mixture was purified and the diastereomers separated by column chromatography using RP(C-18)-silica and a manual 10-50% acetonitrile in water gradient (with 0.05% HCOOH). The resulting fractions were analyzed by analytical RP-LC-MS and pure fractions pooled together and the solvent was evaporated to give (2S)-2-Benzyl-N-((1S)-2,2-dimethyl-1-methylcarbamoyl-propyl)-2,4-dihydroxy-butyramide (0.424 g, 25%) and (2R)-2-Benzyl-N-((1S)-2,2-dimethyl-1-methylcarbamoyl-propyl)-2,4-dihydroxy-butyramide (0.631 g, 38%).

Provenance & Evidence