Formation of stable organometallic products during deprotection of monoallyloxyalcohols

Removal of the allyl group from the monoprotected vicinal diols with the Wilkinsonʹs catalyst followed by treatment with HgO/HgCl2, gave significant amounts of cyclic compounds containing the mercury species as well as the expected diols. Reduction of these organomercurials with sodium borohydride led to replacement of mercury by hydride but, provided unsaturated compounds arising from the cleavage of the C–O bond (α to the mercuric moiety) also.