Studies toward a model for the prediction of the regioselectivity in the Fischer indole synthesis. Part 2. Derivatives of cyclic ketones

A previously reported model for the prediction of the regioselectivity in the Fischer indole synthesis has been applied to the study of three compounds derived from cyclic ketones. The new features added in order to obtain reasonable results in these cases are reported. The results are discussed and show good agreement with the available experimental data. The use of transition state structures and of various possible alternative intermediates is commented on. The unexpected experimental products obtained in one case are qualitatively examined and discussed.