The synthesis of specifically deuterated analogues of Bicyclo[3,3,1]nonan-3-one

Abstract

endo-Bicyclo[3,3,1]nonan-3-ol (1), bicyclo[3,3,1]nonan-3-one (2), and a number of specifically deuterated analogues of these compounds have been synthesized from bicyclo[3,3,1]nonane-3,7-dione (3) by the following procedure.     Reduction of (3) with sodium borohydride gave 1-hydroxy-2- oxaadamantane (4) which was converted into 7-bromobicyclo[3,3,1]nonan- 3-one (6) on treatment with hydrobromic acid. Triphenyltin hydride was used to achieve replacement of the bromine atom by a hydrogen atom to give bicyclo[3,3,1]nonan-3-one (2).     Substitution of sodium borohydride by sodium borodeuteride gave endo-7-deuterobicyclo[3,3,1]nonan-3-one (2b) whereas the use of triphenyltin deuteride in place of triphenyltin hydride led to exo-7- deuterobicyclo[3,3,1]nonan-3-one (2a). The scheme also provided access to the [7-D₂], [6,8-D₄], and [6,7,8-D₆] bicyclo[3,3,1]nonan-3-ones.