lithium diisopropyl amide in tetrahydrofuran T=0°C; 0.25 h; different γ,δ-unsaturated β-oxo esters, alkyl halides or carbonyl compounds; Product distributionMechanism;

piperidine in dichloromethane 72 h; Ambient temperature;

1.1: Yb(OTf)3-H2O / acetonitrile / 24 h / |Inert atmosphere 2.1: sodium hydride / tetrahydrofuran / 0.5 h / |Inert atmosphere 2.2: 4 h / -78 - 20 °C View Scheme