A Mild and Convenient Synthesis of 4-Tosyl-4,5-dihydrooxazoles

A facile and mild synthesis of 4-tosyl-4,5-dihydrooxazoles is described. The reaction between tosyl methyl isocyanide (TosMIC) and cinnamic or aromatic aldehydes is catalyzed by triethylamine, affording trans-5-styryl- or 5-aryl-4- tosyl-4,5-dihydrooxazoles in quantitative yields without further purification. The mild reaction conditions allowed for the first time the use of cinnamaldehyde derivatives with excellent results.