Red Lead as a Selective Oxidant

Abstract

SINCE the fundamental investigations of Dimroth¹, Criegee², Malaprade³ and Fleury⁴, lead tetra-acetate and periodic acid as selective oxidants have played an important part in organic chemistry, particularly for the elucidation of the structure of carbohydrates and related compounds and also from the preparative point of view⁵. It has been found now that red lead (Pb₃O₄) in many cases can be used successfully instead of the above-mentioned oxidants either in aqueous acetic acid medium or in organic solvents containing anhydrous acetic acid. It may be supposed that, in the presence of acetic acid, red lead gives rise with a limited velocity to intermediate formation of lead tetra-acetate which, in the presence of a suitable hydrogen donor, will be promptly reduced to lead diacetate. Therefore, the reaction mixture never contains an excess of tetra-acetate. Hence red lead can be more generally used for the oxidation of aqueous solutions than lead tetra-acetate itself, as this rapidly hydrolyses in aqueous medium into uneffective lead dioxide.