Reduction of Aliphatic and Aromatic Cyclic Ketones to sec??Alcohols by Aqueous Titanium Trichloride/Ammonia System. Steric Course and Mechanistic Implications

A Clerici, N Pastori, O Porta

Index: Clerici, Angelo; Pastori, Nadia; Porta, Ombretta European Journal of Organic Chemistry, 2001 , # 12 p. 2235 - 2243

Full Text: HTML

Citation Number: 11

Abstract

Abstract In contrast to the dissolved metal and metal hydride reductions, the reduction of cyclic ketones by the aqueous TiCl 3/NH 3 system favours the formation of the less thermodynamically stable axial alcohol. The ammonium ion formed in situ is essential for the reduction to proceed because it behaves as a mild Brønsted acid in basic medium and favours the protonation of the intermediate ketyl. The corresponding α-hydroxy radical is ...