sium iodide in ether under reflux into highly sterically hindered alkohols. The mechanism proceeds by a pseudo pinacol type rearrangement of the initially formed carbonyl adduct. The mechanism of the rearrangement was proven by the synthesis of authentic reaction intermediates. The rearrangement was also extended to l-aryl-2,2-dichloro-l-alkanols which behaved analogously towards methylmagnesium iodide.l-Aryl-2,2-dichloro-l-alkanones were shown to rearrange with methyl magne-