Synthesis of 2-deoxy-2-fluoro-D-mannose using fluoride ion.
作者:TERUSHI HARADAHIRA、MINORU MAEDA、HIROKO OMAE、YUJI YANO、MASAHARU KOJIMA
DOI:10.1248/cpb.32.4758
日期:——
Nucleophilic displacement reactions of the 3-O-methyl, and 3-O-benzyl derivatives (5, 11, and 12) of methyl 4, 6-O-benzylidene-2-O-(trifluoromethanesulfonyl)-β-D-glucopyranoside with tetraalkylammonium fluorides in acetonitrile proceeded smoothly to give, with inversion of configuration at C2, the corresponding methyl 2-deoxy-2-fluoro-β-D-mannopyranosides in good yields. Similar treatment of methyl 3-O-benzyl-4, 6-O-benzylidene-2-O-(trifluoromethanesulfonyl)-α-D-glucopyranoside (3) or methyl 3, 4, 6-tri-O-acetyl-2-O-(trifluoromethanesulfonyl)-β-D-glucopyranoside (8) resulted in decreased yield of the fluoro-manno compound. Efficient conversion of these fluorinated intermediates into 2-deoxy-2-fluoro-D-mannose (1) was achieved by heating with acidic reagents. These synthetic sequences could be easily adapted for the preparation of the 18F-labeled analog of 2-deoxy-2-fluoro-D-mannose (1).
3-O-甲基和3-O-苄基衍生物(5、11和12)与四烷基铵氟化物在乙腈中的亲核取代反应顺利进行,在C2位反转构型,得到了相应的甲基2-脱氧-2-氟-β-D-甘露糖苷,产率良好。类似地,对甲基3-O-苄基-4,6-O-苄腈-2-O-(三氟甲磺酰)-α-D-葡萄糖苷(3)或甲基3,4,6-三-O-乙酰-2-O-(三氟甲磺酰)-β-D-葡萄糖苷(8)的处理导致氟化甘露化合物的产率降低。通过与酸性试剂加热,成功地将这些氟化中间体转化为2-脱氧-2-氟-D-甘露糖(1)。这些合成路线可以很容易地适应于制备标记有18F的2-脱氧-2-氟-D-甘露糖(1)类似物。