Structural studies on lipiarmycin. I. Characterization by 1H and 13C NMR spectroscopy and isolation of methyl 2-O-methyl-4-O-homodichloroorsellinate-beta-rhamnoside.

1H and 13C NMR spectral studies of lipiarmycin in CDCl3 and in pyridine-d5 provided evidence for the six partial structures I approximately VI and the two sugar units 1 and 2. Acid methanolysis led to the isolation of methyl 2-O-methyl-4-O-homodichloroorsellinate-beta-rhamnoside, whose structure was determined by spectroscopic methods.