Synthesis of methyl β-d-arabinofuranoside 5-[1d (and l)-myo-inositol 1-phosphate], the capping motif of the lipoarabinomannan of Mycobacterium smegmatis

The total synthesis of methyl β-d-arabinofuranoside 5-(myo-inositol 1-phosphate), the capping motif of the lipoarabinomannan (LAM) of Mycobacterium smegmatis, has been completed. The stereoselective synthesis of β-d-arabinofuranosides has been achieved via an internal aglycon delivery approach using Ogawa and Ito’s method. Coupling with enantiomeric myo-inositol derivatives gave the diastereoisomeric title compounds in good overall yield. Comparison with the natural product firmly established the proposed structure for the capping of the LAM but left the absolute configuration of the myo-inosityl moiety undetermined.