Diastereomerically pure allylboronates bearing the readily available tartrate derivative were obtained via sigmatropic rearrangement. Allyl additions were performed, and the influence of γ-disubstituted allylboronates was studied. Highly γ-substituted boronic esters were found to lead to the corresponding enantiomerically enriched homoallyl alcohols with exclusively E configuration; their synthesis and the mechanism of the reaction is proposed here.