Reaction of perbenzoylated aldopentafuranosyl derivatives of uracil with fluorine in acetic acid afforded perbenzoylated 5-fluorouracil nucleosides. Their methanolysis gave the following free nucleosides of 5-fluorouracil: β-D-ribofuranoside (Id), 2-deoxy-β-D-ribofuranoside (IId), their enantiomers VIII and IX, α-D-ribofuranoside (XIII), 2-deoxy-α-D-ribofuranoside (XV), β-D-arabinofuranoside (IV) and its L-enantiomer X, β-D-xylofuranoside (V) and its α-D-anomer XI, α-L-lyxofuranoside (VI) and 2-deoxy-α-L-lyxofuranoside (VII) and the enantiomers of the latter two compounds, XII and XIV, respectively. Analogously were obtained 5-deoxy-β-D-ribofuranoside (III), β-D-ribopyranoside (XVI) and 1-(S)-(2,3-dihydroxypropyl)-5-fluorouracil (XVIIc). 1-Allyl-5-fluorouracil (XVIII) was prepared by reaction of allyl bromide with 2,4-bis(trimethylsilyloxy)-5-fluoropyrimidine. The cell-free extract from Escherichia coli cleaves all the 5-fluorouracil nucleosides in which the nucleoside carbon atom has the R-configuration and the 3'-hydroxyl of the sugar moiety is in trans-relation to the base. Compounds which have not these structural features are resistant. Besides nucleosides which on enzymatic cleavage afford 5-fluorouracil, also the non-cleavable 1-(2-deoxy-β-L-ribofuranosyl)-5-fluorouracil (IX), 1-(2-deoxy-α-D-ribofuranosyl)-5-fluorouracil (XV) and 1-(2-deoxy-α-D-lyxofuranosyl)-5-fluorouracil (XIV) exhibit an antibacterial effect towards E. coli (ID50 1.0-2.5 . 10-5 M). This effect can be reversed by 2'-deoxyuridine but not by thymidine.
在冰乙酸中,尿嘧啶的苄酰化醛基五糖衍生物与氟反应生成了苄酰化的5-氟尿嘧啶核苷。它们的甲醇解产生了以下的游离5-氟尿嘧啶核苷:β-D-核糖呋喃苷(Id)、2-脱氧-β-D-核糖呋喃苷(IId)、它们的对映异构体VIII和IX、α-D-核糖呋喃苷(XIII)、2-脱氧-α-D-核糖呋喃苷(XV)、β-D-阿拉伯呋喃苷(IV)及其L-对映体X、β-D-木糖呋喃苷(V)及其α-D-异构体XI、α-L-吕糖呋喃苷(VI)和2-脱氧-α-L-吕糖呋喃苷(VII)以及后两种化合物的对映体XII和XIV。类似地获得了5-脱氧-β-D-核糖呋喃苷(III)、β-D-核糖吡喃苷(XVI)和1-(S)-(2,3-二羟基丙基)-5-氟尿嘧啶(XVIIc)。1-丙烯基-5-氟尿嘧啶(XVIII)是通过丙烯基溴和2,4-双(三甲基硅氧基)-5-氟嘧啶反应制备的。大肠杆菌的细胞提取物可裂解所有5-氟尿嘧啶核苷,其中核苷碳原子具有R-构型,糖基的3'-羟基与碱基呈反式关系。不具备这些结构特征的化合物是抗性的。除了在酶解时产生5-氟尿嘧啶的核苷外,还有不可裂解的1-(2-脱氧-β-L-核糖呋喃基)-5-氟尿嘧啶(IX)、1-(2-脱氧-α-D-核糖呋喃苷)-5-氟尿嘧啶(XV)和1-(2-脱氧-α-D-吕糖呋喃苷)-5-氟尿嘧啶(XIV)对大肠杆菌表现出抗菌作用(ID50为1.0-2.5 x 10^-5 M)。这种效应可以被2'-脱氧尿苷而不是胸苷逆转。