Selective Preparation of 6- and 7-(Polyhydroxypropyl)pterins from Pentos-2-uloses

Abstract

The Gabriel-Isay condensation of three types of pentos-2-uloses with 2,5,6-triaminopyrimidin-4(3H)-one (3) was examined under both acidic and basic conditions. The condensation of 5-deoxy- and 5-O-protected pentofuranos-2-uloses with 3 at pH 8 afforded 6-substituted pterins as major isomers, whereas the same reaction at pH 3 yielded the 7-substituted pterins predominantly.