The naturally occurring spironucleoside (+)-hydantocidin 1 was synthes
ized from 1,2:3,4-di-O-isopropylidene-D-psicofuranose using a new oxyg
en-bridged intramolecular Vorbruggen coupling of the N-hydroxyurea 5 i
n presence of a catalytic amount of trimethylsilyltriflate.