(2R,3R,4R)-6-bromo-2-methyl-2-dimethoxymethyl-3,4-epoxy-3,4-dihydro-2H-1-benzopyran 、 N-(4-fluorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine 在
crude product 、 silica gel 、 solvent-n-hexane 、
乙酸乙酯 作用下,
以to give desired compound (175 mg, yield: 53%)的产率得到(2R,3R,4S)-6-bromo-4-[N-(4-fluorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amino]-3-hydroxy-2-methyl-2-dimethoxymethyl-3,4-dihydro-2H-1-benzopyran