Pentoses 2,4-dideoxy, synthesis

Ness, R. K., and H. G. Fletcher, Jr. 2-Deoxy-D-er> f/iro-pentose. X. Synthesis of l,4-Anhydro-3,5-di-0-benzoyl-2-deoxy-D-er> //iro-pentose-l-enol. Derivatives of a Furanose-related Glycal. J. Organ. Chem. (U.S.A.) 28, 435 (1963) Haga, M., and R. K. Ness Preparation and Properties of 3,5-Di-0-p-anisoyl-l,2-dideoxy-D-er> t/iro-pentofuranose-l-ene. Various p-Anisoylated Derivatives of D-Ribofuranose. J. Organ. Chem. (U. S. A.) 30, 158 (1965). 

Allylic esters of fluoroacetic acid were used in the Ireland silyl ketene acetal rearrangement procedures by the Welch group at Albany [164]. For example, Eq. (53) shows a highly diastereoselective rearrangement which formed an early stage in syntheses of 2,3-dideoxy-2-fluoro-3-C-methyl pentose nucleosides [165, 166]. If a stereoselective synthesis of a functionalised monofluorocompound is... 

Dideoxy-D-eryt/zro-hexopyranose (172) has been obtained from 3-deoxy-D-eryt/zro-pentose (171, Scheme 51)248 as an intermediate for the synthesis of the lactone moiety of inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, that lowers cholesterol levels. 

Dideoxy-DL-hexoses were prepared from 137 in the following way the carbon atom chain of the substrate was extended to a seven-carbon atom chain by a low temperature Grignard reaction with methylmagnesium bromide. The product obtained, 145, was separately cis-hydroxylated (to stereoisomeric tetraols 14<) or epoxidized (to epoxides 147). Products 146 and 147 were hydrolyzed and subsequently subjected to Ruff degradation. Pairs of stereoisomeric 2,6-dideoxy-DL-hexoses could be separated by column chromatography. Essentially the same approach served for a synthesis of 2-deoxy-DL-eo f/ ra-pentose. In this case compound 138 (X = OH) was used as a substrate for epoxidation. 

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