Optically active 5-(hydroxyalkyl)- and 5-(aminoalkyl)pyrazolidin-3-ones by ring-chain transformation of α,β-unsaturated lactones or lactams with hydrazines

Article abstract of DOI:10.1002/jlac.199619961013

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 optically active hydroxylalkyl- or aminoalkylpyrazolidin-3-ones 4 and 6. These pyrazolidin-3-ones are further transformed to tosylated, acetylated or silylated derivatives 9 or react with benzaldehyde to give the azomethine imine 10. VCH Verlagsgesellschaft mbH, 1996.