Deoxygenation reactions 1,1 -thiocarbonyldiimidazole

Xanthates, which are easily prepared from the reaction of alcohols, carbon disulfide, and methyl iodide in the presence of a base, or from the reaction of alcohols with N,Nf-thiocarbonyldiimidazole, can generally be used for the deoxygenation of alcohols to the corresponding hydrocarbons. So, eq. 3.19 shows the deoxygenative cyclization of... 

Monodeoxygenation of 1,2- and 1,3-diols was achieved via their cyclic thiocarbonates, prepared from the diol and A/,A/ -thiocarbonyldiimidazole, by reaction with BusSnH-AIBN followed by alkaline hydrolysis (presumably, F would also be effective for the cleavage step). Equation (14) shows this process applied to synthesis of a derivative (73) of 5-deoxyglucose. Exclusive secondary deoxygenation is expected on the basis of radical stability in contrast, the derivative (72) was readily converted by an ionic process to an intermediate suitable for 6-deoxygenadon, since treatment with KI gave (74) quantitatively. 

The second approach to the synthesis of CNT 31 [81] involves opening of the 2, 3 -anhydro-P-D-lyxonucleoside 50 with lithium cyanide to give stereo-selectively 51 (R = Trityl). Attempts to deoxygenate the 2 -OH group by reaction with Ar,AT-thiocarbonyldiimidazole gave the a,P-unsaturated nitrile 48 (R = trityl). Reduction of the double bond of 48 (R = trityl) with triethylsilane and tris(triphenylphosphine)rhodium (I) chloride gave a mixture of the two... 

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