New diastereospecific synthesis of 2′,3′-dideoxy-2′- or 3′-C2-branched- or 2′,3′-α-fused-isoxazolidine nucleosides directly from the seconucleoside

Article abstract of DOI:10.1016/S0040-4020(01)90437-5

The first diastereospecific syntheses of [3.3.0]-α-fused-isoxazolidine nucleosides 20 or 24, and 2′-or 3′-C₂-branched-2′,3′-dideoxynucleosides 14 or 16 have been reported starting directly from 2′,3′-seconucleoside 3. The key steps involve the unsymmetrical modification of the 2′- or 3′-hydroxyl in the seconucleoside 3 to give pure 8 (3→4→7→8) or 11 (3→5→10→11) and their diastereospecific recyclisation to the furanose moiety to give the title compounds either by radical or [2+3] cycloaddition reaction.