NMR spectroscopic analysis of the borate diol esters of methyl apiofuranosides

The borate diol esters formed by reacting methyl β-d- and methyl β-l-apiofuranosides with boric acid were studied by 11B, 1H and 13C NMR spectroscopy, and by FABMS. Methyl β-d-apiofuranoside was shown to form more stable borate diol diesters and a monoester than those of methyl β-l-apiofuranoside. The borate diol diesters of methyl β-d-apiofuranoside are present as two diastereomers in approximately equal molar ratios.