Reaction of isopropylidene derivative I with thionyl chloride in hexamethylphosphoric triamide afforded chloro derivative II. Removal of the isopropylidene group in II by treatment with a cation-exchanging resin (H+ form) gave the free chloro nucleoside III. reduction of the chloro derivative II with tributylstannane and subsequent removal of the isopropylidene group yielded deoxy derivative V. This was protected with tert-butyldiphenylsilyl group and converted into the mesylate VII. Elimination of the mesyl group followed by desilylation gave 1-(2,3-dideoxy-4-C-methyl-β-D-glycero-pent-2-enofuranosyl)thymine (IX) which was hydrogenated to afford 1-(2,3-dideoxy-4-C-methyl-β-D-glycero-pentofuranosyl)thymine (X). 1-(1-C-Azidomethyl-2-deoxy-β-D-threo-pentofuranosyl)thymine (XIII) was prepared by mesylation of the isopropylidene derivative I, nucleophilic substitution of the mesyl group with azide and removal of the isopropylidene group.
异丙基亚甲基衍
生物I与
氯化硫酰在六
甲基膦酰胺中反应,生成
氯代衍
生物II。用阳离子交换
树脂(H+形式)处理II中的异丙基亚甲基基团,得到游离
氯代核苷III。用三
丁基锡还原
氯代衍
生物II,并随后去除异丙基亚甲基基团,得到脱氧衍
生物V。这个化合物被叔丁基二苯基
硅基保护,并转化为
甲磺酸盐VII。去除甲磺基,随后去除
硅基,得到1-(2,3-二去氧-4-C-甲基-β-D-
glycero-pent-2-enofuranosyl)胸腺
嘧啶(IX),通过氢化反应得到1-(2,3-二去氧-4-C-甲基-β-D-
glycero-pentofuranosyl)胸腺
嘧啶(X)。通过异丙基亚甲基衍
生物I的甲磺化,甲磺基的亲核取代反应以及去除异丙基亚甲基基团,制备出1-(1-C-Azidomethyl-2-deoxy-β-D-
threo-pentofuranosyl)胸腺
嘧啶(XIII)。