A NEW SYNTHETIC METHOD OF PREPARING IODOHYDRIN AND BROMOHYDRIN DERIVATIVES THROUGH IN-SITU GENERATION OF HYPOHALOUS ACIDS FROM H5IO6 AND NABRO3 IN THE PRESENCE OF NAHSO3

Hypohydrous acids such as hypoiodous acid (IOH) and hypobromous acid (BrOH) were found to be easily generated from H5IO6 and NaBrO3 in the presence of an appropriate reducing agent such as NaHSO3. Iodohydrin and bromohydrin derivatives were synthesized in good yields from the reaction of a wide variety of organic compounds bearing carbon-carbon double bonds, with H5IO6 or NaBrO3 and NaHSO3. The iodohydroxylation of internal alkenes was achieved with high stereoselectivity to give anti products, although no stereoselectivity was observed in the bromohydroxylation of these alkenes. It was found that allylic alcohols undergo iodohydroxylation in anti-Markovnikov fashion to form iodo diols in good yields. Treatment of alkynes with H5IO6 combined with NaHSO3 afforded the corresponding ketones in fair yields, but the same treatment with NaBrO3 rather than H5IO6 produced the corresponding alpha,alpha-dibromo ketones along with small amounts of the dibromoalkenes.