Lithium diisobutyl-t-butoxyaluminum hydride, a new and efficient reducing agent for the conversion of esters to aldehydes

Lithium diisobutyl-t-butoxyaluminum hydride (LDBBA), easily prepared by reaction of lithium t-butoxide with DIBALH, readily reacts with common aromatic and aliphatic esters to give the corresponding aldehydes in 74-88% yield at 0 °C. Especially, this reagent proved to be the most effective partial reducing agent for conversion of isopropyl esters to aldehydes, in most cases, with >90% yield under the same reaction temperature.