72525-43-0Relevant articles and documents
A New Synthetic Use of Nucleoside N1-Oxides
MacCoss, Malcolm,Ryu, Eung K.,White, Robert S.,Last, Robert L.
, p. 788 - 794 (1980)
The use of adenosine N1-oxide derivatives to prevent intramolecular cyclization during nucleophilic displacement reactions on the sugar moiety is described.This new synthetic use of N1-oxides is illustrated by the synthesis of 5'-O-(p-toluenesulfonyl)-2',3'-O-isopropylideneadenosine N1-oxide (6) and subsequent displacement of the 5' substituent with iodide or azide under conditions which lead exclusively to N3->5' intramolecular cyclization in the absence of the N1-oxide.Similarly, reaction of 2',3'-O-isopropylideneadenosine N1-oxide with methyltriphenoxyphosphonium iodide produces 5'-iodo-5'-deoxy-2',3'-O-isopropylideneadenosine N1-oxide (7) with no observable cyclization.In addition, 2',3'-anhydroadenosine N1-oxide (17) is shown to be stable under conditions that lead to complete N3->3' intramolecular cyclization in the unprotected 2',3'-anhydroadenosine (14).Reduction of the N1-oxide to produce the parent nucleoside is readily achieved by using hexachlorodisilane or by hydrogenating over Raney nickel.The mechanistical rationale and implications for additional nucleoside transformations are discussed.
