[4165-53-1] · C14H23AlO · Diisobutylaluminum Phenoxide · (MW 234.32)
(base for aldol condensation of methyl ketones2)
Solubility: sol toluene and THF.
Preparative Method: prepared in situ by careful addition of Diisobutylaluminum Hydride to a THF solution of 1 equiv of phenol.2
Handling, Storage, and Precautions: solutions are moisture and air sensitive and should be prepared and handled under an inert atmosphere; use in a fume hood.
Diisobutylaluminum phenoxide has been used as a base in conjunction with Pyridine for effecting regiospecific aldol condensations of methyl ketones via the corresponding kinetic aluminum enolates. As an intermolecular example, the condensation of 2-octanone gave a mixture of isomeric 9-methylpentadecenones in good yield (eq 1).2
The intramolecular aldol condensation of 2,15-hexadecanedione, which required the use of the reagent in large excess, gave a mixture of isomeric 3-methylcyclopentadecenones (eq 2).3 Subsequent hydrogenation over Palladium on Carbon gave (±)-muscone in good overall yield, compared to earlier efforts using the corresponding magnesium enolate.4
Gary W. Morrow
The University of Dayton, OH, USA