Structural investigations (NMR) show that both 1-dimethylaminoallyllithium (4) and potassium (2) exist exclusively in the endo conformation in THF. Ab initio calculations also conclude that the endo-structure is thermodynamically more stable than the exo- conformation. Cryoscopic measurements indicate that the potassium compound 2 is a monomer under the experimental conditions studied here. The lithium compound 4 ...