Epoxidation of Flavones by Dimethyldioxirane

Article abstract of DOI:10.1021/jo00026a020

The synthesis of epoxides 2 by epoxidation of flavones 1 with isolated dimethyldioxirane (as acetone solution) at subambient temperatures is reported.These labile epoxides were isolated and completely characterized by UV, IR, 1H and 13C NMR, MS, and C,H analyses.Warming to room temperature led to rearrangement to afford quantitatively the 3-hydroxyflavones 3b,h,i,n.Treatment of the epoxides 2b,f with methanol led to the 3-hydroxy-2-methoxyflavanones 4b,f, as a mixture of cis and trans isomers.