No abstract

1-Iodobicyclo[1.1.1]pentane reacts cleanly with t-butyllithium by a metal-halogen exchange process to give 1-lithiobicyclo[1.1.1]pentane. Both 1-chlorobicyclo[1.1.1]pentane and the parent hydrocarbon bicyclo [1.1.1]pentane are found to be inert to t-butyllithium.

Multipath couplings involving 1H-1H, and 13C-13C nuclei in a variety of 1-substituted bicycloalkanes are treated according to additivity principles based on empirical coupling increments derived from model hydrocarbons. The coupling constants are essentially additive in practically all series except for derivatives of bicyclo [1.1.1]pentane; non-additivities of several couplings in the latter are ascribed to the effects of contributions arising from through-space bridgehead-bridgehead interactions, as well as from mutual electronic perturbations between the different pathways. The results are compared with those derived previously from theoretical calculations, which also have some difficulty in reproducing the experimental data in the case of the bicyclo [1.1.1] pentyl system.

A series of dimercury(1) complexes of the type [Hg2L2] [ClO4]2 has been prepared with heterocyclic nitrogen donor ligands. Complexes with 2-ethylpyridine and 4-benzylpyridine were of the form [Hg2L3.7] [ClO4]2 and [Hg2L4] [ClO4]2 respectively. The formation of a stable complex is found to be dependent on the effective base strength of the ligand.

1-Bromobicyclo[1.1.1]pentane (3) is found to undergo solvolysis faster than t-butyl bromide in 80% aqueous ethanol, and gives 3-methylenecyclobutanol (7) exclusively. Products arising from capture of the bicyclo[1.1.1] pentyl cation (5) were not detected.