A solvent-free photooxygenation of 5-methoxyoxazoles 1a–j embedded in porphrin-loaded polystyrene beads as solid support is described and applied for the synthesis of 3H-1,2,4-dioxazole derivatives 2a–j. Acid catalysed hydrolysis of 3H-1,2,4-dioxazole derivatives gave α-amino-α-hydroxy carboxylic acid derivatives 3a–j. The structural elucidation of the new compounds were carried on the basis of spectral and X-ray analyses.