Synthesis and Structural Analysis of 4-Deoxy-4-(hydroxyphosphinyl and phenylphosphinyl)- d -ribofuranoses

Methyl 2,3-O-isopropylidene-β-d-ribopyranoside gave efficiently (in 4 steps) methyl 4-deoxy-4-[dimethoxyphosphinyl and (methoxy)phenylphosphinyl]-2,3-O-isopropylidene-β-d-ribopyranosides (ca. 30% overall yield). These were led (in 2–3 steps) to the title compounds and then converted into 1,2,3,5-tetra-O-acetyl-4-deoxy-4-(methoxyphosphinyl and phenylphosphinyl)-d-ribofuranoses, whose structures and 3T2 (and 2T3) conformations were established by spectroscopy.