An Inexpensive Air-Stable Titanium-Based System for the Conversion of Esters to Primary Alcohols

Article abstract of DOI:10.1021/jo00129a031

Polymethylhydroxiloxane, when combined with titanium(IV) isopropoxide, provides a convenient system for the conversion of esters to the corresponding primary alcohols in the presence of a wide range of functional groups.Reactions are carried out as mixtures of the neat reaction components; workup with aqueous alkaline THF affords primary alcohols in good to excellent yields.The system tolerates primary alkyl bromides and iodides, olefins, epoxides, and alkynes.Steric differentiation of methyl and tert-butyl esters is also possible.The results observed in the parent and related reactions argue against pathways involving Lewis-acid catalysis and anionic hydridosilicate-mediated reductions, and instead support a neutral titanium hydride complex or strongly associated titanium/silane complex as the active reducing agent.