Addition of kinetic boron enolates generated from β-alkoxy methyl ketones to aldehydes. Density functional theory calculations on the transition structures

Herein we report that good to excellent levels of 1,5-anti stereoinduction are obtained in boron enolate aldol reactions of 1,2-syn β-alkoxy methyl ketones with achiral aldehydes, when the β-alkoxy protecting group is part of a benzylidene acetal. We have also investigated the effects of the ligands on boron, the α-, β-, and γ-substituents and the β-alkoxy protecting group on the boron enolates, using density functional theory (B3LYP) and Møller–Plesset perturbation theory (MP2) calculations.