To 2.0 g (0.008 mol) of 22 in 60 mL of 2-propanol at room temperature were added 0.72 g (0.008 mol) of 3-amino-1, 2-propanediol and 0.8 g (0.008 mol) of triethylamine. After the mixture was stirred for 16 h, the solvent was removed on the rotary evaporator, and the residue was flash chromatographed on silica gel (230-400 mesh) with 10% methanol/chloroform elution. The product had Rf 0.4 and was isolated as a yellow solid ( ...