138-52-3

16643-37-1

138-52-3

GENERAL METHODS: The compound (CAS:16643-37-1) was used as raw material and mixed with the acceptor ArOH (3.0 eq.) in anhydrous DCM (0.1 M), to which was added freshly prepared BF3-OEt2 solution (1.0 eq., 1 M, in anhydrous DCM). The reaction mixture was stirred at room temperature for 1 h. Subsequently, the progress of the reaction was monitored by TLC (30:70; EtOAc: hexane). Upon completion of the reaction, the reaction was quenched by the addition of NaHCO3 (aqueous), the mixture was extracted with DCM, the organic phase was washed with brine, dried over anhydrous Na2SO4, filtered and concentrated in vacuum. The α/β ratio of the crude product was analyzed by 1H NMR. The residue was dissolved in anhydrous methanol (0.3 M) and freshly prepared MeONa solution (0.25 equiv., 0.5 M methanol solution) was added and stirred for 1 h at room temperature. The reaction mixture was neutralized with Amberlite IR-120H+ , filtered and concentrated in vacuum to give a white solid. Purification by fast column chromatography (10:90; MeOH:DCM) removes excess ArOH to give β-D isoheads, which are finally recrystallized in hot ethanol.