Optically Active 5-(Hydroxyalkyl)- and 5-(Aminoalkyl)pyrazolidin-3-ones by Ring-Chain Transformation of α,β-Unsaturated Lactones or Lactams with Hydrazines
α,β-Unsaturated lactones or lactams 1 react with hydrazines 2 via Michael-like addition and subsequent ring transformation by nucleophilic attack of the hitherto unchanged hydrazine nitrogen atom at the carbonyl carbon atom. The addition is highly trans-stereoselective, thus affording opticallyactive hydroxylalkyl- or aminoalkylpyrazolidin-3-ones 4 and 6. These pyrazolidin-3-ones are further transformed