Deoxygenations iodotrimethylsilane

Iodotrimethylsilane formed in situ from the reaction of chlorotrimethylsilane and sodium iodide, also effects the conversion of 2-ene-l,4-diols to 1,3-dienes (equation 16)46. Allylic thionocarbonates on heating with triphenylphosphite undergo deoxygenation (Corey-Winter reaction) to generate olefins47. This procedure has been used for making hexatrienes (equation 17)47b. 

Deoxygenation of 1,4-endooxides.1 The transformation of a 1,4-endooxide (1) to the corresponding aromatic hydrocarbon (2) can be effected in high yield with iodotrimethylsilane. The deoxygenation was used for a novel synthesis of 1,4-di-methylphenanthrene (3) as shown in equation (I). 

Reduction of oi-ketols. a-Ketols are deoxygenated to the corresponding ketones in 75-95% yield by reaction with 2.5 equiv. of iodotrimethylsilane inCHCb or CH2CI2 at room temperature. 

Deoxygenation of aieohols and ethers. Treatment of alcohols and methyl or trimethylsilyl ethers in acetonitrile with this iodotrimethylsilane equivalent and then zinc (previously activated with aqueous hydrochloric acid) and a little acetic acid results in deoxygenation to alkanes, usually in 60-90% yield. Presumably an alkyl iodide is an intermediate. 

Deoxygenation of sulfoxides. Alkyl sulfoxides are reduced to sulfides on treatment with either bromo- or iodotrimethylsilane in CCI4 at room temperature for 30 minutes (yields generally around 80%). Some halogenated products are also formed in the case of diaryl or dibenzyl sulfoxides. 

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