Área de Química Orgánica, Departamento de Química, Facultad de Ciencias, Universidad de Burgos, Pza. Misael Bañuelos s/n, 09001 Burgos, Spain.
Org Lett. 2020 Oct 16;22(20):8070-8075. doi: 10.1021/acs.orglett.0c03014. Epub 2020 Sep 29.
α-Lithiobenzyl ethers, generated by selective α-lithiation, undergo an aldol-Tishchenko reaction upon treatment with carboxylic esters and paraformaldehyde. The reaction of the organolithium with the carboxylate generates an intermediate enolate that, after formaldehyde addition, affords 1,2,3-triol derivatives in a straightforward and one-pot manner. These products are obtained as single diastereoisomers bearing a quaternary stereocenter. The complete diastereocontrol of the aldol-Tishchenko process is attributed to stereoelectronic preferences in the transition state.
α-锂代苯甲醚经选择性α-锂化反应生成，与羧酸酯和多聚甲醛反应后发生羟醛-Tishchenko 反应。有机锂与羧酸根反应生成烯醇盐中间体，加甲醛后，以直接和一锅法的方式得到 1,2,3-三醇衍生物。这些产物作为单一对映异构体获得，带有一个季立体中心。羟醛-Tishchenko 过程的完全非对映控制归因于过渡态中的立体电子偏好。
