Hydrophilically augmented glycosyl carborane derivatives for incorporation in antibody conjugation reagents

The synthesis of a series of O-glycosyl carboranes is described. The reactions of hydroxyalkyl carboranes and esterified carbohydrates, in the presence of a Lewis acid catalyst, proved to be stereoselective. Reactions of these carboranes with tri-O-acetyl-D-glucal or di-O-acetyl-D-xylal and a catalytic amount of BF 3 •OEt 2 favored the formation of α anomers, while the β anomer was the major product of the SnCl 4 -catalyzed reaction. The 1 H and 13 C NMR spectra were analyzed by using several one-dimensional and two-dimensional techniques; the chemical shifts and coupling interactions of all atoms were unequivocally assigned