The reaction of lithium triethylborohydride with the 2′, 3′-di-Op-tolyl-sulphonyl derivatives of 9-/bg-D-ribofuranosyladenine, 9-β-D-arabinofuranosyl-adenine, 9-β-D- xylofuranosyladenine and 9-β-D-lyxofuranosyladenine was studied. The reaction of 2′, 3′-
