Polarographic behaviour of trans-oxymercurated allenes

The electroreduction of trans-oxymercurated allenes has been examined at the dme in 50% dioxane-water medium. These organomercurials give two well-defined and well-separated waves. The first one-electron reversible step is followed by a second one-electron irreversible step. Variation of the diffusion currents with temperature, height of the mercury reservoir and concentration indicate the diffusion-controlled nature of the waves. According to the suggested mechanism of the electroreduction, trans-2-chloromercury-3-methoxycyclotridecene captures an electron to generate an organomercury free radical in the first step. The organomercury free radical takes up another electron simultaneously with a proton to give the ether, resulting in the second wave. The effect of ring size and stereochemistry on the half-wave potentials is discussed