Enantioselective, electrocatalytic lactonization of methyl-substituted diols on a TEMPO-modified graphite felt electrode in the presence of (-)-sparteine

Article abstract of DOI:10.1246/cl.1996.1043

A TEMPO (2,2,6,6-tetramethylpiperidin-1-yloxyl)-modified graphite felt electrode afforded enantioselective, electrocatalytic lactonized products of (S)-(-)-3,4,5,6-tetrahydro-4-melhyl-2-pyranone, (S)-(-)-4,5-dihydro-4-methyl-2(3H)-furanone and (S)-(-)-4,5-dihydro-5-methyl-2(3H)-furanone from 3-methylpentane-1,5-diol, (S)-(-)-2-methylbutane-1,4-diol and racemic pentane-1,4-diol, respectively, in enantiomeric excess more than 95%, in the presence of (-)-sparteine in acetonitrile. The current efficiency and isolated yield of former two lactones were more than 90%.