https://sciforum.net/paper/3700
A new synthesis of 4-oxo-4,5-dihydro-1,3-oxazolium perchlorates from D-pantoamide - SCIFORUM
The reaction of D-(–)-pantolactone with ammonia leads to the formation of D-pantoamide, which reacts with Ас2О and HClO4 to give...
a newsynthesisoxodihydrooxazolium