Reduction of Aromatic Carbonyl Compounds Promoted by Titanium Trichloride in Basic Media. Stereochemistry Studies

Article abstract of DOI:10.1021/jo00201a015

Aromatic ketones, which are not affected by Ti(III) chloride in acidic medium, react smoothly in basic media to afford the reductively coupled products according to the increase of the reducing power of Ti(III) ion with increasing pH.Benzil, benzoin, and methoxybenzoin give the corresponding alcohols.The observed stereochemistry is discussed in terms of intermolecular Ti bridging control (dl > meso) when intramolecular Ti complexation is prevented and in terms of steric control (meso > dl) when two sites of potential Ti complexation are available in the molecule.Thereagent, Ti(III) chloride, is selective in that many other functional groups are unaffected by it.