Stochastic search for the conformations of bicyclic hydrocarbons

The stochastic search method was used to seek all of the conformations for 32 bicyclic hydrocarbons. Since the size of the random kick used is sufficient to invert the configurations of carbon atoms, the out, out, in, out, and in, in conformations were all found in a single stochastic run for each hydrocarbon. The lowest energy conformer obtained in each category is reported. A modification of the program to prevent inversion of configuration was developed. It was found, in some cases, that in, in and out, out isomers for some bicyclic hydrocarbons were interconverted by this modified program, presumably through the “homeomorphic isomerization” process described by Park and Simmons. A statistical formula for estimating the approximate chances of finding (or missing) any conformer as a function of the number of random kicks given is derived and presented.