Synthesis of L‐glycero‐α‐D‐manno‐heptopyranose‐containing disaccharide derivatives of the Neisseria meningitidis dephosphorylated inner‐core region

Hydroxymethylation of correctly protected alkyl α‐D‐manno‐hexodialdo‐1,5‐pyranosides with [(isopropoxydimethylsilyl)methyl]magnesium chloride affords the corresponding silane intermediates, the isopropoxydimethylsilyl group of which can be unmasked with hydrogen peroxide. The L‐glycero‐α‐D‐manno‐heptopyranose (L‐α‐D‐Hepp) derivatives thus obtained can be subsequently used for the preparation of the disaccharides β‐D‐Glcp‐(1‐4)‐L‐α‐D‐Hepp‐OMe and β‐D‐Glcp‐(1‐4)‐L‐α‐D‐Hepp‐O‐(CH₂)₃NH₂.