Synthesis of Morpholino Nucleosides Starting From Enantiopure Glycidol

A protocol for the synthesis of modified morpholino monomers was performed in few steps through the condensation between 6-hydroxymethyl-morpholine acetal and nucleobases under Lewis acid conditions. The key common precursor for the targets - 6-hydroxymethyl-morpholine acetal - is easly synthesised via oxirane ring opening of optically pure glycidol by N-nosyl aminoacetoaldheyde as nucleophile, followed by a O-benzoylation/ring-closure tandem reaction sequence. Using readily available building blocks, this strategy allows access to diversified optically pure morpholino monomers in good yields and anomeric ratio