Double Diastereoselection in Aldol Reactions Mediated by Dicyclohexylchloroborane between Chiral Aldehydes and a Chiral Ethyl Ketone Derived from <scp>l</scp>-Erythrulose. Synthesis of a C<sub>1</sub>−C<sub>9</sub> Fragment of the Structure of the Antifungal Metabolite Soraphen A<sub>1</sub><sub>α</sub>
作者:Santiago Díaz-Oltra、Juan Murga、Eva Falomir、Miguel Carda、Gabriel Peris、J. Alberto Marco
DOI:10.1021/jo051307p
日期:2005.9.1
diastereoselections have been observed in the aldol reactions of a range of chiral aldehydes with the dicyclohexylboron enolate of a chiral ethyl ketone related to l-erythrulose. As was previously observed in the corresponding aldol reactions with l-erythrulose derivatives, the Felkin−Anh model provides an adequate explanation for the stereochemical outcome of reactions with chiral α-methyl aldehydes. However, a
在一系列手性醛与与1-赤藓糖有关的手性乙基酮的二环己基硼烯醇酸酯的醛醇缩合反应中已经观察到匹配的和错配的非对映异构选择。如先前在与1-赤藓糖衍生物的相应羟醛反应中观察到的,Felkin-Anh模型为与手性α-甲基醛反应的立体化学结果提供了充分的解释。但是,只有在Cornforth模型中,才能令人满意地说明使用α-氧化醛所观察到的结果。如本文中所描述的方法的实际应用中,一个C 1 -C 9的抗真菌大环内酯类soraphen A中的结构的片段1 α 已经以收敛和立体选择的方式进行了准备。