Base-promoted reactions of α-azido ketones with aldehydes and ketones: A novel entry to α-azido-β-hydroxy ketones and 2,5-dihydro-5-hydroxyoxazoles

Article abstract of DOI:10.1021/jo00113a015

The base-promoted reaction of α-azido ketones with aldehydes and ketones provides a new and simple route to either α-azido-β-hydroxy ketones, which are valuable 1,2,3-trifunctionalized synthons, or 2,5-dihydro-5-hydroxyoxazoles, which are a little known type of oxazoline. These two products are formed by the electrophilic trapping of two different anions that are produced sequentially during the reaction. The α-azido-β-hydroxy ketones are formed by an aldol reaction between an enolate of the α-azidoketone and an aldehyde. The 2,5-dihydro-5-hydroxyoxazoles are formed by electrophilic trapping of an imino anion which is produced by nitrogen loss from the α-azido ketone enolate.