The preparation of polymer bound β-ketoesters and their conversion into an array of oxazoles

A series of diverse polymer bound β-ketoesters have been prepared using a transesterification reaction between t-butyl β-ketoesters and a hydroxybutyl functionalized JandaJel resin. Additionally, these highly useful polymer bound substrates have also been prepared using a transesterification reaction with commercially available methyl or ethyl β-ketoesters using lithium perchlorate as a catalyst. The polymer bound β-ketoesters were then converted into the corresponding α-diazo-β-ketoesters using standard diazo transfer conditions and these products were utilized in the synthesis of an array of oxazoles.