SOME NOVEL NUCLEOSIDE REARRANGEMENTS EFFECTED BY (DIETHYLAMINO)SULPHUR TRIFLUORIDE - SYNTHESIS AND ANTIVIRAL PROPERTIES OF SOME FLUORINE-CONTAINING 3'-AZIDO-3'-DEOXYTHYMIDINE DERIVATIVES
Ae. Lloyd et al., SOME NOVEL NUCLEOSIDE REARRANGEMENTS EFFECTED BY (DIETHYLAMINO)SULPHUR TRIFLUORIDE - SYNTHESIS AND ANTIVIRAL PROPERTIES OF SOME FLUORINE-CONTAINING 3'-AZIDO-3'-DEOXYTHYMIDINE DERIVATIVES, Journal of fluorine chemistry, 62(2-3), 1993, pp. 145-160
The reaction of pyrimidine nucleoside 5'-aldehydes with (diethylamino)
sulphur trifluoride (DAST) to produce 5'-deoxy-5',5'-difluoronucleosid
es is reported. The preferred reaction is the production of the O2,5'-
anhydro-5'-fluoronucleoside. If this is prevented by substitution at O
4 or N-3 then, in the former case, either DAST no longer reacts or und
er drastic conditions the C(1')-N(1) bond breaks and the heterocyclic
base remains joined by C-5' --> O2 to a glycosyl fluoride. In the latt
er case, the 5'-aldehyde of 2',3'-O-isopropylideneuridine gives the 5'
-deoxy-5',5'-difluoro compound as the sole identifiable product. With
the 5'-aldehyde of AZT [suitably protected at N-31 as starting materia
l, treatment with DAST yields a diastereoisomeric mixture of glycosyl
fluorides and a derivative of 5'-deoxy-5',5'-difluoro AZT from which 3
'-azido-3',5'-dideoxy-5',5'-difluorothymidine could be isolated. This
compound is not toxic nor has it any activity against human immunodefi
ciency virus type-1 (HIV-1) at concentrations up to 100 muM.