Al-isopropoxydiisobutylalane: a study of the effect of solvent on the rate and stereoselectivity of cyclic ketone reduction.
The effect of solvent on the rate and stereoselectivity of cyclic ketone reduction by Al-isopropoxydiisobutylalane (DIBA(i)OPr) has been investigated. In dichloromethane, DIBA(i)OPr behaves as a bulky reducing agent, approaching the carbonyl group along an equatorial trajectory to produce the axial alcohol with >10:1 stereoselectivity. In sharp contrast, reduction in toluene gives the complementary outcome, affording the thermodynamically more stable isomer with >99:1 stereoselectivity.
Bahia
Perdip S
PS
School of Chemistry, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
Jones
Matthew A
MA
Snaith
John S
JS