Milieux hyperbasiques: préparation de carbanions en α d'amides N,N-disubstitués. Synthèse de β- et γ-hydroxyamides et de γ-butyrolactones

The α anions of N,N-disubstituted carboxamides can be conveniently prepared by treatment with "activated" lithium dialkylamides in HMPT. They react with aldehydes and ketones and lead to β-hydroxyamides; furthermore the ring opening of epoxides affords γ-hydroxyamides which may be cyclized in situ to γ-butyrolactones