In the presence of a catalytic amount of proline and silica gel, a mixture of ketene silyl acetals and 2-allyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolane underwent 1,4- and subsequently 1,2-addition with acrolein to give δ-hydroxyesters in good yields in a highly diastereoselective manner.
在催化量的脯
氨酸和
硅胶存在下,酮烯
硅基醛与2-烯丙基-4,4,5,5-四甲基-1,3,2-二氧
硼烷的混合物与
丙烯醛发生1,4-加成,随后进行1,2-加成,生成δ-羟基酯,反应具有良好的产率和高度的非对映选择性。