Stereoselective Synthesis of Alcohols, XX. Diastereoselective Addition of γ‐Alkoxyallylboronates to Aldehydes

Abstract
Both the (Z)‐ and the (E)‐γ‐alkoxy‐substituted allylboronates 1 and 3 have been prepared. They add to aldehydes with a diastereoselectivity generally exceeding 90% to give the syn‐ (2) and anti‐diol derivatives 4, respectively. The structure of one of these adducts has been established by conversion into exo‐brevicomin (26).