Alternative linear structures associated with regular Lagrangians. Weyl   quantization and the Von Neumann uniqueness theorem
  We discuss how the existence of a regular Lagrangian description on the tangent bundle $TQ$ of some configuration space $Q$ allows for the construction of a linear structure on $TQ$ that can be considered as "adapted" to the given dynamical system. The fact then that many dynamical systems admit alternative Lagrangian descriptions opens the possibility to use the Weyl scheme to quantize the system in different non equivalent ways, "evading", so to speak, the von Neumann uniqueness theorem. 
E. Ercolessi, A. Ibort, G. Marmo and G. Morandi