Unsaturated carbohydrates. Part XIV. The isomerisation of hex-2-enopyranosylpurine nucleoside derivatives

Abstract

In corroboration of previous reports, tri-O-acetyl-D-glucal has been found to give 4′,6′-di-O-acetyl-2′,3′-dideoxy-D-erythro-hex-2-enopyranosyl nucleosides on condensation with substituted purines. These products, however, are now shown to be formed under kinetic control; on heating with acids or in inert high-boiling solvents they rearrange to afford isomers with 3-deoxyglycal structures having the bases attached at C-3.