ACTIVATED CARBOXYLATES FROM THE PHOTOOXYGENATION OF OXAZOLES; APPLICATION TO THE SYNTHESIS OF RECIFEIOLIDE, CURVULARIN AND MACROLIDES

Article abstract of DOI:10.1016/S0040-4020(01)93281-8

Oxazoles may be used as masked forms of activated carboxylic acids since they readily form triamides on reaction with singlet oxygen.With 2-alkyl-4,5-diphenyloxazoles, the triamides formed on photooxygenation undergo selective nucleophilic attack at the acyl carbonyl derived from the 2-oxazole position.Using 2-(ο-hydroxyalkyl)-4,5-diphenyloxazoles as subsrates, the oxidation-acylation sequence may be employed for the synthesis of macrolides including (+/-)-recifeiolide and (+/-)-di-O-methylcurvularin.