Hypoiodous acid, reaction with alkenes

With the exception of iodomethane (CH3I) and neopentyl iodide ((CH3)3CCH2l) all the reactions of 0( P) with the alkyl iodides were found to produce as major product an alkene. An example is shown for 1-iodobutane in Figure 9. Hypoiodous acid (HOI), the probable coproduct in each case, was also identified via its known infrared absorptions at 3620 and 1070 cm (Bames et al., 1992). This compound is, however, very short-lived under the conditions of the experiments and was only visible in the infrared spectrum in the initial stages of the reaction (Figure 10) and could therefore not be quantified. For many of the alkenes calibrated reference spectra were available and the yield of the alkene has been determined. Oxygen atoms also react fairly rapidly with alkenes, therefore, the reaction of O atoms with the alkenes has been taken into consideration when calculating the alkene yields from the O + Rl reactions. The yields and the identity of the alkene for the respective O + RI reactions are listed in Table 1. 

OL-Iodo ketones, a-lodo ketones are usually prepared by reaction of enol acetates with NIS. A new method involves reaction of an alkene with silver chromate and iodine in the presence of pyridine. The actual reagent is presumably a mixed anhydride of hypoiodous acid and chromic acid. Dichloromethane is the most useful solvent. ... 

Asensio and coworkers reported a low temperature oxidation of iodomethane with DMDO to afford a pale yellow precipitate of iodosylmethane (20, Scheme 2.10) [104]. Upon raising the temperature to -40 °C, in the presence of moisture iodosylmethane decomposes to form the unstable hypoiodous acid, HOI, which can be trapped in situ by an alkene to afford iodohydrins. The formation of MelO has also been detected in the photochemical reaction of iodomethane with ozone in an argon matrix at 17 K [105], A similar low-temperature reaction of trilluoroiodomethane affords the unstable CF3IO, which was identified by infrared spectroscopy [106]. 

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