Dinitrogen Tetraoxide Complexes of Iron(III) and Copper(II) Nitrates as Versatile Reagents for Organic Syntheses. Efficient Oxidative Deprotection of Silyl or Tetrahydropyranyl Ethers, Acetals, and Thioacetals

Fe(NO3)3·1.5N2O4 and Cu(NO3)2·N2O4 are efficient reagents for oxidative deprotection of various silyl and tetrahydropyranyl ethers, acetals, and thioacetals in aprotic organic solvents. Fe(NO3)3·1.5N2O4 is also able to perform the reactions efficiently in the absence of solvents at room temperature. Over-oxidation of the products has not been observed in these reactions. A synergic effect of N2O4 upon the oxidation abilities of metal nitrates is observed.