2-Substituted Bicyclopentanes

Article abstract of DOI:10.1021/jo00058a015

A simple procedure has been developed for the conversion of 2-phenylbicyclo<1.1.1>pentan-2-ol to 2 phenyl-bicyclo<1.1.1>pentane.Oxidation gives bicyclo<1.1.1>pentane-2-carboxylic acid which may be converted to the amine, the nitro derivative, and the phenyl ketone.The pK_a values for the carboxylic acid and related acids were determined, and the pK_a's of the amine hydrochloride and related compounds also were studied.The pK_a's of the amine were approximately linearly related to the percent s character determined from the (1)H-C NMR coupling constants.The pK_aof the nitro derivative was determined, and the kinetic acidity of the phenyl ketone also was measured.The relationship of the differences in the energy to the changes in strain energy is discussed.In an effort to prepare a compound with substituents at both the 1- and 2-positions, the reaction of 1,3-dinitrobicyclo<1.1.1>pentane with oxalyl chloride was examined.The reaction had a suprising course, leading to 2,2-dichloro-1,3-dinitrobicyclo<1.1.1>pentane.