SARCIDUMITOL, A NEW NATURALLY OCCURRING 2,6-DIDEOXY-DISACCHARIDITOL FROM Sarcostemma acidum

HMQC and HMBC experiments were carried out to determine the planar structure of 1. The HMQC spectrum firstly allowed the assignments of all protons to their bonding carbons. In the HMBC spectrum (Fig. 1), long-range correlations of H-1/C-3, H-2/C-4, OMe-3/C-3, H-3/C-5, H 3 -6/C-5, and H 3 -6/C-4 established the carbon skeleton of the hexounit, the correlations of H 2 -1/C-3, H 2 -2/C-3, OMe-3/C-3, H-4/C-2, H-4/C-3, H-4/C-5, and H 3 -6/C-4 indicated the carbon skeleton of the hexitol unit, and the correlation H-1 and C-4 showed the 14 linkage of the two units. Thus, the planar structure of sarcidumitol was unambiguously determined to be 2,6-dideoxy-3-O-methyl-ribo-hexo-(14)-2,6-dideoxy-3-Omethyl-ribo-hexitol (1).