Synthesis of a Nucleoside Analog Bearing a Branched Difunctional Sidechain Using the Palladium-Mediated Cyclization of a γ-Oxoallene

Article abstract of DOI:10.1016/S0040-4039(00)78432-2

The aldehyde 8 was synthesized in high yield and with excellent stereoselectivity by treating a protected 3-hydroxypropanal with Corey's chiral B-propargyl boradiazoline reagent.Cyclization of this γ-oxoallene with palladium(II) in the presence of methanol and carbon monoxide produced the furanoside 9 with excellent stereoselectivity for the D-deoxyribose geometry.The furanoside 9 was converted to the branched extended sidechain deoxythymidine analog 11 by reduction, protection,and β-stereoselective Vorbruggen coupling.The hydroboration/oxidation of 10 to yield the deoxyribofuranoside analog 13, bearing two sidechain hydroxyl groups, was also demonstrated.