An easy access to protected (4S, 5R)-5-alkyl-4-hydroxy-2-pyrrolidinones and their use as versatile synthetic intermediates

Article abstract of DOI:10.1016/S0040-4020(98)00734-0

A versatile approach to enantiopure (4S, 5R)-5-alkyl-4-hydroxy-2- pyrrolidinones is described. The key steps involve a regioselective Grignard reagent addition to (S)-malimides, and diastereoselective reductive dehydroxylation of the resulting hemi-azaketals. The flexibility of this methodology has been demonstrated by the synthesis of (2R, 3R)-3-amino-1- benzyl-2-methylpyrrolidine, the parent diamine of antipsychotic agent, emonapride, and the unnatural enantiomer of the β-hydroxy-γ-amino acid residue of hapalosin in lactam form.