Diisobutylaluminum Phenoxide1


[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.

Aldol Condensations.

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

1. Carey, F. A.; Sundberg, R. J. Advanced Organic Chemistry, 3rd ed.; Plenum: New York, 1990; Part B, pp 55-79.
2. Tsuji, J.; Yamada, T.; Kaito, M.; Mandai, T. TL 1979, 2257.
3. Tsuji, J.; Kaito, M.; Mandai, T. BCJ 1980, 53, 1417.
4. Stoll, M.; Rouve, A. HCA 1947, 30, 2019.

Gary W. Morrow

The University of Dayton, OH, USA

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.