Synthesis of 3-trialkylsilyl pyrazoles from β-oxo acylsilanes

The synthesis of β-oxo acylsilanes via cyclic sulfates is described and applied to carbohydrates. These compounds are used for the synthesis of new silylated pyrazoles linked to a carbohydrate moiety by the addition of hydrazines. The regiochemistry of the reaction was determined by NMR analyses (1H/13C and 1H/15N correlations).