Dear Ms. Pratibha Srivastava,

Your question does not have many details (temperature, secondary products formed...), so I am guessing DMSO is used as solvent. Then, the oxidation can be seen as a two step process where an initial carbonyl alfa-iodination intermediate is formed; then a beta-elimination produces the flavone, as can be seen in Goel, R.N., Mahesh, V.B. & Seshadri, T.R. Proc. Indian Acad. Sci. (1958) 47: 184. doi:10.1007/BF03052638

Hope this answer may help you.

Best regards,

JM Urbina G.

Thank you very much