Reaction of peroxyacetals with silyl ketene acetals: synthesis of 3-peroxyalkanoates and 3-peroxyalkanals

Lewis acid-mediated reaction of monoperoxyacetals with silyl ketene acetals (SKAs) provides an efficient approach to 3-peroxyalkanoates. Propionate SKAs react with aliphatic peroxyacetals to furnish 3-peroxy-2-methyl alkanoates with modest anti-selectivity. Although acetate and thioacetate SKAs are less reactive, the latter react with unsaturated peroxyacetals to furnish peroxyalkenoates and -alkadienoates which undergo chemoselective reduction to 3-peroxyalkenals and 3-peroxyalkadienals.