Aldoses, diethyl dithioacetals 1-thio

Displacements Catalyzed by Adds.—The acid-catalyzed mercaptala-tion reaction with ethanethiol normally leads to the aldose diethyl dithio-acetal, but, in anhydrous reaction media, further ethylthio substituents may be introduced into the molecule, usually at C-2. Brigl and coworkers found that ethanethiol and hydrogen chloride convert 3,4,5,6-tetra-O-benzoyl-D-glucose diethyl dithioacetal into 3,4,5,6-tetra-O-benz-oyl-2-)S-ethyl-2-thio-D-glucose (mannose) diethyl dithioacetal. The diethyl... 

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