Spectral evidence has been found which indicates that ∝-hydroxy ferrocenyl alcohols may form hydrogen bonds directly with the iron atom. Investigations are now in progress of the isomerization of the exo and of the endo forms of ∝-hydroxy-1,2-tetram.ethylene ferrocene toward the equilibrium mixture, using aluminum isopropoxide in isopropanol plus a trace of acetone as the isomerizing agent. Preliminary results indicate the equilibrium ratio of endo isomer to exo to be roughly 3:1 (75% endo; 25% exo).
Alexander Newell Lyon (Thu,) studied this question.