Polar Substituent Effects in 1,3-Disubstituted Bicyclopentanes

Article abstract of DOI:10.1021/jo00146a031

The pKa's of eight 3-substituted bicyclo<1.1.1>pentanecarboxylic acids have been measured and found to correlate well with ?_I constants.The value of ρ_I (2.23 +/- 0.12) is large but not large enough to propose any special perturbation of normal field-inductive effects by the close proximity (about 1.88 Ae) of the bridgehead carbons.Also determined were the products and rates of solvolyses of the p-nitrobenzoates of three 3-substituted 1-<2-hydroxy-2-propyl)bicyclo<1.1.1>pentanes.The products were primarily unrearranged, and the rates again showed no surprisingsubstituent effects.A practical synthesis of 1,3-disubstituted bicyclo<1.1.1>pentanes has been developed and is described.