OPTICALLY-ACTIVE 5-(HYDROXYALKYL)PYRAZOLIDIN-3-ONE AND 5-(AMINOALKYL)PYRAZOLIDIN-3-ONE BY RING-CHAIN TRANSFORMATION OF ALPHA,BETA-UNSATURATED LACTONES OR LACTAMS WITH HYDRAZINES

alpha,beta-Unsaturated lactones or lactams 1 react with hydrazines 2 v ia Michael-Like addition and subsequent ring transformation by nucleop hilic attack of the hitherto unchanged hydrazine nitrogen atom at the carbonyl carbon atom. The addition is highly trans-stereoselective, th us affording optically active hydroxylalkyl- or aminoalkylpyrazolidin- 3-ones 4 and 6. These pyrazolidin-3-ones are further transformed to to sylated, acetylated or silylated derivatives 9 or react with benzaldeh yde to give the azomethine imine 10.