Catalytic Meerwein-Pondorf-Verley reduction by simple aluminum complexes.

[reaction: see text] Catalytic MPV reduction was successfully carried out using simple aluminum precatalysts. Alkylaluminum reagents were converted to a low-aggregation aluminum alkoxide that was highly active for the MPV reduction of several carbonyl substrates in high yield (50-99%) using (i)PrOH as the reducing agent. A high degree of cis/trans selectivity was achieved in the reduction of 2-methylcyclohexanone (cis/trans = 20/80) by (i)PrOH. When chiral hydride sources were utilized in the reduction of 2-chloroacetophenone, high enantioselectivity (68-80% ee) was observed.