Synthesis of some new Spiro(Pyran-4,2′- Oxazolidine) and Pyridoxazolidine Derivatives

Ketene S,S-acetal 2 reacts with aminoethanol to afford 2-(1-acetal -2-oxo propylldine)oxazolldine 3 which was allowed to react with some active methylene compounds having an α- cyano or α-keto group to give spiro(pyran -4,2′-oxazolldine) derivatives 6-11. Compound 3 reacted with some α, β -unsaturated nltriles to afford the corresponding pyrldoxazolldine derivatives 12a-h through a nucleophillc addition and cyclization.