The importance of electrostatic effects in controlling π-facial stereoselectivity in nucleophilic additions to carbonyl compounds: an ab initio MO study of a prototype chelation model

Ab initio MO calculations on the complete set of diastereoisomeric transition structures for the addition of lithium hydride to fluoroethanal and 2-fluoropropanal revealed that the most stable transition structure for each system is dominated by electrostatic attraction between Li and F and this results in the formation of the Cram chelation control product for the latter aldehyde.