Synthesis of serine-linked phosphatidylinositol mannosides (PIMs)

The 6-O-allyl group of inositol mannoside (D)-6 was used for the generation of O-linked serine residues via a sequence of dihydroxylation, selective 3-O-protection, introduction of the 2-amino group, deprotection, and oxidation of the 3-position. Attachment of the phosphatidyl residue to 1-O of the inositol moiety and complete deprotection furnished target molecules (D)-1 and (D)-2. Alternatively, instead of introduction of a 6-O-allyl group, 2,3-dihydroxy propanylation of the 6-O-position of the inositol moiety using a silyl-protected cyclic sulfate of glycerol was possible. Thus, target molecule (L)-3 was obtained. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.