The stereotriad D has been the most elusive one to obtain in the course of the  synthesis of polyketide derived natural products. Many research groups involved  in such endeavours have contributed original approaches to this seemingly simple  structural unit. The most popular approach is to generate a building block that  contains all the stereocenters of the triad D. The molecular skeleton may then  be extended from such a building block in two directions. We describe here our  own route to such building blocks, being based on an enantioselective  crotylboration of methacrolein followed by a diastereoselective hydroboration  reaction.
                                    在合成多酮衍生
天然产物的过程中,立体三聚体 D 一直是最难以获得的结构单元。许多从事此类工作的研究小组都针对这一看似简单的结构单元提出了独创的方法。最流行的方法是生成一个包含三元组 D 的所有立体中心的结构单元。我们在此介绍自己获得这种构筑基块的途径,它基于甲基
丙烯醛的对映选择性羰基
硼化反应,然后是非对映选择性氢
硼化反应。