[3 + 2] Cycloaddition of Oxazol-5-(4H)-ones with Nitrones for Diastereoselective Synthesis of Isoxazolidin-5-ones.

In the presence of TMSCl, the [3 + 2] cycloaddition of oxazol-5-(4H)-ones with nitrones proceeded smoothly and furnished the desired isoxazolidin-5-ones with high diastereoselectivities in reasonable chemical yields. The chemical structure of the title compounds was firmly confirmed by X-ray single-crystal structure analysis.