The synthesis of the isomeric 2′-deoxypseudouridines

Abstract

Reaction of 3,4-isopropylidene-2-deoxyribose with 2,4-dit-butoxy-5-lithiopyrimidine gives the protected allo- and altro-polyols (I). Cyclisation by 5′ -tosylation then treatment with methoxide affords respectively the protected β and α-pyranosyl nucleosides (II). Mild acid treatment of allo- and altro-(I) gives the corresponding unprotected polyols (III). Acid-catalysed isomerisation of β-2-deoxypseudouridine and cyclisation of (III) is discussed.