Diethyl di thioacetal

Tri-O-benzyl-D-arabinofuranose stirred at 0° with a mixture of ethanethiol and anhydrous Mg-sulfate satd. with HGl, and the product treated with benzoyl chloride in pyridine 4-0-benzoyl-2,3,5-tri-0-benzyl-D-arabinose diethyl di-thioacetal (Y 94%) added with Drierite to henzyl alcohol, stirred 1 hr. after addition of Cd-carbonate and HgClg the product isolated after 2 hrs. -> 4-0-benzoyl-2,3,5-tri-0-henzyl-D-arabinose dibenzyl acetal (Y 80%) stirred 16 hrs. under reflux at 56-58° with BaO, Drierite, methyl iodide, and dimethylformamide, the resulting crude 2,3,5-tri-0-henzyl-4-0-methyl-D-arabinose dibenzyl acetal hydrogenated ca. 2.5 hrs. with palladous chloride in methanol, and the product refluxed 1.5 hrs. in 0.5 N HGl to hydrolyze the methyl glycoside present 4-0-methyl-y -D-arabinopyranose (Y 64%). — This pathway is not dependent on the stereochemistry of the aldose. H. G. Fletcher, Jr., and H. W. Diehl, J. Org. Ghem. 30, 2321 (1965). 

A new di-O-benzylidene derivative (13) of D-arabinose diethyl di-thioacetal was obtained by benzylidenation with -dimethoxytoluene,... 

Borate complexes have been utilized by Brigl and Griiner47 to effect partial esterification. Anhydrous D-glucose and metaboric acid dissolved in acetone give a complex which exhibits the analysis of a diborate. Reaction of the latter with an excess of benzoyl chloride gives 2,6-di-O-benzoyl-D-glucose (XL). D-Mannitol likewise forms a diborate, which produces the 1,6-di-O-benzoyl derivative (XLI) upon benzoylation. In the presence of boric acid, D-glucose diethyl thioacetal yields the 6-benzoate (XLII). In the non-aqueous medium the formation of complexes... 

Formation.— Treatment of epichlorohydrin with potassium thioacetate yields 3-acetoxythietan " 2-chloromethylthiiran with potassium thioacetate or potassium di-(0-ethyl)dithiophosphate gives the corresponding 3-sub-stituted thietan. 3,3-Bis(hydroxymethyl)thietan is obtained by treatment of pentaerythritol with diethyl carbonate followed by treatment of the cyclic carbonate with potassium thiocyanate. ... 

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