Chiral phosphoric acid catalyzed addition of dihydropyrans to N -acyl imines: Stereocontrolled access to enantioenriched spirocyclic oxazoletetrahydropyrans with three contiguous stereocenters

摘要

Figure presented Dihydropyran derivatives readily undergo addition to N-acyl imines in the presence of chiral phosphoric acids. This addition process yields an attractive product that is capable of a tandem oxidative-cyclization via an epoxide intermediate.