Aldol–Tishchenko Reaction of α-Oxy Ketones: Diastereoselective Synthesis of 1,2,3-Triol Derivatives

α-Oxy ketones, easily accessible by conventional routes, can be selectively deprotonated generating an enolate intermediate, which upon treatment with paraformaldehyde undergoes an aldol–Tishchenko reaction, leading to relevant 1,2,3-triol fragments in a totally diastereoselective manner. The excellent stereocontrol in the generation of a quaternary stereocenter is attributed to stereoelectronic effects in the Evans intermediate. This methodology allows overcoming some limitations of our previously reported strategy, based on the reaction of α-lithiobenzyl ethers with esters and paraformaldehyde, broadening the scope of the obtained polyols. Synthetic applications of this process include the preparation of a new dilignol model and some functionalized oxetanes.
Ministerio de Ciencia e Innovación and FEDER (CTQ2016-75023-C2-1-P), and Junta de Castilla y León and FEDER (BU291P18, BU049P20). The project leading to these results has also received funding from the “la Caixa” Foundation, under agreement LCF/PR/PR18/51130007) (CAIXA-UBU001). A postdoctoral contract (S.S.-P.) and a predoctoral contract (C.S.) were funded by Junta de Castilla y León and FEDER and Ministerio de Educación (FPU), respectively