Highly Diastereoselective Preparation of Aldol Products Using New Functionalized Allylic Aluminum Reagents

Chloro-substituted triethylsilyl
enol ethers derived from cyclo­hexanone
and related ketones are converted with aluminum powder in the presence
of indium trichloride to functionalized allylic aluminum reagents
which represent a new type of synthetic equivalent of metal enolates.
These allylic organometallics undergo highly diastereo­selective
additions to aldehydes and methyl aryl ketones, giving aldol products
with a β-quaternary center.