Nucleosides. CXLIX. Novel and practical synthesis of .ALPHA.-monofluoro- and .ALPHA.,.ALPHA.-difluorothymidine (F-TDR and F2-TDR).
作者:JASENKA MATULIC ADAMIC、KYOICHI A. WATANABE
DOI:10.1248/cpb.36.1554
日期:——
Di-O-tert-butyldiphenylsilyl (BDPS)-thymidine (2) was converted to α-bromo-3', 5'-di-O-BDPS-thymidine (3) by photobromination. Crude 3 was hydrolyzed to the α-hydroxythymidine derivative 4 which was oxidized with MnO2 to the 5-formyluracil nucleoside 5. Fluorination of 4 with diethylamino-sulfur trifluoride afforded the protected α-fluorothymidine 6. Similarly, 5 was converted into the α, α-difluorothymine nucleoside 7. These protected fluorothymidines (6 and 7) were deblocked by treatment with tetra-n-butylammonium fluoride to give α-fluorothymidine(8, F-TDR) and α, α-difluorothymidine (9, F2-TDR).
二-O-叔丁基二苯基硅烷基(BDPS)-胸苷(2)经光溴化反应转化为 α-溴-3',5'-二-O-BDPS-胸苷(3)。粗 3 被水解为 α-羟基胸苷衍生物 4,该衍生物被 MnO2 氧化为 5-甲酰尿嘧啶核苷 5。用二乙胺基三氟化硫对 4 进行氟化处理,可得到受保护的 α-氟胸苷 6。同样,5 也转化成了 α、α-二氟胸腺嘧啶核苷 7。这些受保护的氟胸苷(6 和 7)经四正丁基氟化铵处理后脱锁,得到α-氟胸苷(8,F-TDR)和α,α-二氟胸苷(9,F2-TDR)。