First asymmetric synthesis of orthoquinone monoketal enantiomers via anodic oxidation

Org Lett. 2004 Nov 25;6(24):4571-3. doi: 10.1021/ol048030k.


An asymmetric synthesis of orthoquinone monoketals was accomplished using anodic oxidation to convert aryl methyl ethers bearing a chiral ethanol unit into orthoquinone bisketals, followed by monohydrolysis of their dimethyl ketal unit. All four possible stereoisomers were generated in a diastereoselective manner by varying the attachment point of the chiral pro-ketal alcoholic auxiliary to the starting arene. A preliminary screening of subsequent nucleophilic addition reactions confirmed the potential utility of these synthons in asymmetric synthesis. [reaction: see text]