Abstract
Fluorinated nitrones derived from fluoral and difluoroacetaldehyde react with thioketones via [3 + 2] cycloaddition yielding 1,4,2-oxathiazolidines in a regioselective manner. Unexpectedly, cycloaliphatic thioketones react faster than aromatic thioketones. Due to the presence of a fluorinated alkyl group, the cycloadducts display a remarkable stability and do not decompose at room temperature in the crystalline form nor in solution.