Umemura E, Tsuchiya T, Kobayashi Y, Tanaka K
Institute of Bioorganic Chemistry, Kawasaki, Japan.
Carbohydr Res. 1992 Feb 7;224:141-63. doi: 10.1016/0008-6215(92)84101-w.
Reactions of 4,6-disubstituted 2,3-anhydro-alpha-D-allopyranosides with potassium hydrogenfluoride (KHF2) in ethane-1,2-diol gave, by oxirane-ring opening, the corresponding 2-deoxy-2-fluoro-alpha-D-altro- and 3-deoxy-3-fluoro-alpha-D-gluco-pyranosyl derivatives, with the latter always in preponderance. The influence of the substituents at C-4 and C-6 on the D-gluco-D-altro ratio (r) have been studied by molecular mechanics, and the discrepancy between the experimental and calculated r values has been positively utilized to measure the effects of solvation and hydrogen bonding relative to the C-4 and C-6 substituents. By application of this reaction, 3'-deoxy-3'-fluorokanamycin A has been prepared by treatment of a 2',3'-anhydro-3'-epikanamycin A derivative (35) with KHF2. 3'-Chloro-3'-deoxykanamycin A was also prepared.
4,6-二取代的2,3-脱水-α-D-阿洛吡喃糖苷与氟化氢钾（KHF₂）在1,2-乙二醇中反应，通过环氧乙烷环开环，生成相应的2-脱氧-2-氟-α-D-阿卓糖基和3-脱氧-3-氟-α-D-葡萄糖基衍生物，其中后者总是占优势。通过分子力学研究了C-4和C-6位取代基对D-葡萄糖-D-阿卓糖比例（r）的影响，并积极利用实验值与计算值之间的差异来衡量相对于C-4和C-6位取代基的溶剂化和氢键作用的影响。通过应用该反应，用KHF₂处理2',3'-脱水-3'-表卡那霉素A衍生物（35）制备了3'-脱氧-3'-氟卡那霉素A。还制备了3'-氯-3'-脱氧卡那霉素A。
