Synthesis of 3-Mono- and 3,5-Difunctionalized Noriceanes (Tetracyclo2,6.04,9>undecanes via Oxymetallation of 3,5-Dehydronoriceane (Pentacyclo2,6.03,5.04,9>undecane). Oxidation of Bicyclopentane System by Mercury(II), Thallium(III), and Lead(IV) Acetates

Article abstract of DOI:10.1246/bcsj.53.3318

Oxymercuration of 3,5-dehydronoriceane (1) followed by sodium borohydride reduction gives exclusively endo-3-noriceanol in 80 percent yield.The trans-1,3--addition organomercury intermediate is isolated as endo-3-acetoxy-exo-5-(chloromercurio)noriceane.Oxidation of 1 with thallium(III) acetate gives three diacetates, exo,exo- and endo,exo-3,5-diacetoxynoriceanes <(9) and(10)> and endo,exo-4,5-diacetoxytetracyclo<5.3.1.0^2,6.0^3,9>undecane (11) in a ratio of 6:61:27 in 68percent combined yield.The analogous oxidation of 1 with lead(IV) acetate gives 9, 10, and 11 in a ratio of 50:25:25 in 80percent combined yield.On the basis of the stereochemistry of the products as well as the products distribution, we propose that 1,3-bridged metanol ion intervenes and plays an important role in the oxymetallation reaction of bicyclo<2.1.0>pentane system.