Total Synthesis of Phospholipomannan of Candida albicans

• DOI: 10.1021/acs.joc.0c00402
• Publication Date: 2020-05-19T09:32:59Z
• Authors: Veeranjaneyulu Ga...; Asif Ali; Parvinder Pal Singh; Ram A. Vishwakarma
• Keywords: Phosphonate; Moiety; Phosphodiester bond

First, total synthesis of the cell surface phospholipomannan anchor [β-Manp-(1 → 2)-β-Manp]n-(1 2)-β-Manp-(1 2)-α-Manp-1 P-(O 6)-α-Manp-(1 2)-Inositol-1-P-(O 1)-phytoceramide Candida albicans is reported. The target (PLM) poses synthetic challenges such as unusual kinetically controlled (1 2)-β-oligomannan domain, anomeric phosphodiester, and unique phytoceramide lipid tail linked to glycan through a phosphate group. PLM was accomplished using convergent block approach three main appropriately protected building blocks: 2)-β-tetramannan repeats, pseudodisaccharide, phytoceramide-1-H-phosphonate. most challenging domain synthesized in one pot preactivation method. phytoceramide-1-H-phosphonate an enantioselective A3 three-component coupling reaction. Finally, moiety coupled with pseudodisaccharide followed by deacetylation produce acceptor, which on subsequent tetramannosyl-H-phosphonate provided fully anchor. Final deprotection successfully achieved Pearlman's hydrogenation.