Treatment of methyl 3,4-di-O-acyl-2,6-dideoxy-α-D-ribo-hexo-pyranoside1or2with trimethylsilyl halide leads to the formation of a complex mixture of α-D-ribo-hexopyranosyl halides3or5together with the educts1or2as well as their β-anomers8or9. The bromides3and5, suitable for glycosidations, are preferably obtained by reaction of the digitoxose acetate derivatives6and7, respectively, which in turn are prepared from1and2by mild acetolysis. Further reaction of the halides3to5with trimethylsilyl halides gives rise to a quantitative formation of the 2,3,6-trideoxy-4-0-acyl-3-halo-α-D -arabino-hexopyranosyl halides10to12. In another reaction sequence starting with the olivose triacetate20the formation of10via the halide13is demonstrated. Structural evidence for the halides10to12is given by1H NMR data as well as by analyses of their glycosides14to19. The results support a mechanistic interpretation for the formation of10to12via a 3,4-acetoxonium ion as the key intermediate obtained from3by an SNfi and from13and SN2i step. Final conversion into the terminal halodeoxy compounds10to12proceeds by and SN2 reaction with the halide ion.