ORGANOBORON COMPOUNDS. CDV. BROMINATION OF 2-ISOPROPYL-2-BORAADAMANTANE

Article abstract of DOI:10.1016/0022-328X(83)85037-2

Bromination of 2-isopropyl-2-boraadamantane in CH2Cl2 proceeds simultaneously by both radical and electrophilic mechanisms.The first involves elimination of HBr and formation of 2-(2-bromo-2-propyl)-2-boraadamantane; this rearranges, under the action of nucleophilic reagents, to a derivative of 4-borahomoadamantane, which converts, on oxidation, to 3α-hydroxy-7α-(2-hydroxy-2-propyl)bicyclo<3.3.1>nonane.The second direction includes cleavage of a B-C(isopropyl) bond with formation of i-PrBr and 2-bromo-2-boraadamantane, oxidation of which leads to 3α, 7α-dihydroxybicyclo<3.3.1>nonane.In the presence of H2O, a solvated Br⁺ also takes part in the bromination, which results in formation of hydroxy (3-noradamantyl)isopropylborane, which is oxidized to 3-noradamantanol.Depending on the reaction conditions one of the three possible directions may predominate.