Anionic cyclizations are becoming increasingly popular for the preparation of carbocyclic and heterocyclic ring systems.[1]We have found that the stannane 1, on transmetallation with butyllithium, gives the 3-substituted pyrrolidine products 2 after electrophilic quench.2, 3 and 4The intermediate α-amino-methyllithium cyclizes onto the unactivated alkene to give the 3-lithiomethylpyrrolidine, which can be trapped with electrophiles. We wished to ...