1.Synthesis of α-C-Galactosylceramide via Diastereoselective Aziridination: The New Immunostimulant 4'-epi-C-Glycoside of KRN7000.
Chang YJ1, Hsuan YC2, Lai AC1, Han YC1, Hou DR2. Org Lett. 2016 Feb 19;18(4):808-11. doi: 10.1021/acs.orglett.6b00090. Epub 2016 Feb 4.
A new immunostimulant, the 4'-epimer of α-C-GalCer, was synthesized from a C2-symmetric dienediol and α-C-allyl galactoside. The intramolecular aziridination and the following reductive ring opening provided the core of the aliphatic amino alcohol with excellent regio- and stereocontrol. The new immunostimulants 3d and 3e gave a better polarized Th1-type cytokine response in murine NKT cells than the benchmarked α-C-GalCer.
2.Intramolecular nitrogen delivery for the synthesis of C-glycosphingolipids. Application to the C-glycoside of the immunostimulant KRN7000.
Altiti AS1, Mootoo DR. Org Lett. 2014 Mar 7;16(5):1466-9. doi: 10.1021/ol5002686. Epub 2014 Feb 21.
The key reaction in this approach to C-glycosphingolipids is the stereoselective iodocyclization of a sugar-linked homoallylic carbonimidothioate. E and Z reaction substrates were assembled in a convergent fashion via an alkene metathesis strategy and exhibited the same alkene facial selectivity in the iodocyclization irrespective of alkene geometry, although the E alkene was found to be less reactive.