Tetrabutylammonium fluoride promoted intramolecular nucleophilic attack of an ester group on a carbodiimide: Preparation of 1,3-oxazolin-5-ones and 3,1-benzoxazin-4-ones

Article abstract of DOI:10.1055/s-1996-4284

Functionalized carbodiimides bearing an ester group either at the α or β position undergo cyclization in the presence of tetrabutylammonium fluoride (TBAF) under mild conditions to give 1,3-oxazolin-5-ones or 3,1-benzoxazin-4-ones in synthetically useful yields.