A highly stereoselective synthesis of anti-HIV 2',3'-dideoxy- and 2',3'-didehydro-2',3'-dideoxynucleosides

A convenient synthesis of 2′,3′‐dideoxyinosine‐13C5 and related 2′,3′‐dideoxyadenosine‐13C5

“…From 5 this strategy 5 led to ddI-13 C 5 as illustrated in Scheme 2. A solution of 5 in 1,2-dichloroethane was added to a pre-generated 6 silylated 6-chloropurine in a solution of 1,2-dichloroethane at À251C, and the reaction was initiated by treatment with TMSOTf.…”

“…From a batch of this starting material ddI-13 C 5 was made in 27% overall yield in seven steps and ddA-13 C 5 in five steps and 14% overall yield. The known synthesis of ddI-13 C 5 from glucose-13 C 6 took 18-steps ; therefore the present work is a substantial improvement.…”

Synthesis of 2,3-Didehydro-2,3-dideoxynucleosides via Nucleoside Route.

“…A large number of studies have been described in literature regarding the synthesis of d4Ns via the sugar route [27][28][29][30][31][32][33][34][35][36][37][38].…”

Olefin Metathesis Route to Antiviral Nucleosides

“…The synthesis of 2',3'-dideoxynucleosides (ddNs) or 2',3'-didehydro-dideoxynucleosides (d4Ns) from nucleosides has been extensively reviewed [36]. In the case of the latter, their synthesis has been mainly achieved through a radical reaction (Barton deoxygenation) [37], a fragmentation of 2',3'-cyclic orthoformates (Eastwood olefination) or 2',3'-cyclic-thionocarbonates (Corey-Winter reaction) [38], a reductive elimination of 2'(3')-acetoxy-3'(2')-halogeno derivatives (Mattocks reaction) [39], a deoxygenation of 5'-O-protected nucleoside 2',3'-dimesylate by treatment with Te 2-or ArSe -[40], stereoselective coupling from 2-phenylseleno [41] or 2'-phenylsulfeno sugars [42]. While those methods are based onto the modification of 2'-and/or 3'-OH of the intact ribose moiety, the use of a RCM protocol, a promising tool in nucleoside chemistry [24,32,43], for the formation of the unsaturated cyclic system of nucleosides could be a straightforward approach to the d4Ns.…”