Condensation of 1,2-di-O-acetyl-3,5-di-O-benzoyl-4-C-benzoyloxymethyl-L-arabinofuranose with N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleoside I, which upon partial deacetylation and subsequent mesylation was converted into 9-(3,5-di-O-benzoyl-4-C-benzoyloxymethyl-2-O-methanesulfonyl-α-L-arabinofuranosyl)adenine (III). 9-(2,5,6-Tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-α-L-arabinofuranosyl)-N6-benzoyladenine (V) was obtained by condensation of 1,2,5-tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-L-arabinose with N6-benzoyladenine. Reaction of mesyl derivatives III and V with methanolic sodium methoxide afforded 2',3'-anhydro nucleosides VIa and VIIa, which were acetylated to give 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-ribofuranosyl)adenine (VIb) and 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-lyxofuranosyl)adenine (VIIb). Epoxy derivative VIb was cleaved with bromotrimethylsilane to 9-(5-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIIa); the same reaction with epoxy derivative VIIb afforded a mixture of 9-(5-O-acetyl-4-C-acetoxymethyl- 2-bromo-2-deoxy-α-L-xylofuranosyl)adenine (IXa) and 9-(5-O-acetyl-4-C-acetoxymethyl-3-bromo- 3-deoxy-α-L-arabinofuranosyl)adenine (Xa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-4-C-hydroxymethyl-α-L-erythro-pentofuranosyl)adenine (VIIIc), 9-(2-deoxy-4-C-hydroxymethyl- α-L-threo-pentofuranosyl)adenine (IXc) and 9-(3-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)adenine (Xc). 9-(2,5-Di-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIId), prepared by acetylation of VIIIa, on reductive elimination with Cu/Zn couple and subsequent deacetylation afforded 9-(2,3-dideoxy-4-C-hydroxymethyl-α-L-glycero-pent-2-enofuranosyl)adenine (XIb). 9-(2,3-Dideoxy-4-C-hydroxymethyl-α-L-glycero-pentofuranosyl)adenine (XIIb) was obtained either by catalytic hydrogenation of bromo derivative VIIId, followed by deacetylation, or by catalytic hydrogenation of didehydro derivative XIb. The nucleosides synthesized were tested for antiviral activity.
1,2-二-O-乙酰基-3,5-二-O-苯甲酰基-4-C-苯甲酰氧甲基-L-阿拉伯呋喃糖与N6-苯甲酰腺嘌呤在四氯化锡催化下缩合,得到核苷I,经过部分去乙酰化和随后的甲磺酰化,转化为9-(3,5-二-O-苯甲酰基-4-C-苯甲酰氧甲基-2-O-甲磺酰基-α-L-阿拉伯呋喃糖基)腺嘌呤(III)。1,2,5-三-O-乙酰基-4-C-乙酰氧甲基-3-O-甲磺酰基-L-阿拉伯糖与N6-苯甲酰腺嘌呤缩合,得到9-(2,5,6-三-O-乙酰基-4-C-乙酰氧甲基-3-O-甲磺酰基-α-L-阿拉伯呋喃糖基)-N6-苯甲酰腺嘌呤(V)。将甲烷醇钠甲醇溶液与甲磺酰衍生物III和V反应,得到2',3'-脱水核苷VIa和VIIa,它们被乙酰化,得到9-(5-O-乙酰基-4-C-乙酰氧甲基-2,3-脱水-α-L-核糖呋喃基)腺嘌呤(VIb)和9-(5-O-乙酰基-4-C-乙酰氧甲基-2,3-脱水-α-L-吕克索呋喃基)腺嘌呤(VIIb)。环氧衍生物VIb被溴三甲基硅烷裂解成9-(5-O-乙酰基-4-C-乙酰氧甲基-2-溴-2-脱氧-α-L-阿拉伯呋喃糖基)腺嘌呤(VIIIa);用环氧衍生物VIIb进行相同的反应,得到9-(5-O-乙酰基-4-C-乙酰氧甲基-2-溴-2-脱氧-α-L-吕克索呋喃糖基)(IXa)和9-(5-O-乙酰基-4-C-乙酰氧甲基-3-溴-3-脱氧-α-L-阿拉伯呋喃糖基)(Xa)的混合物。它们通过三丁基锡脱卤素化和随后的去乙酰化,得到9-(2-脱氧-4-C-羟甲基-α-L-erythro-戊糖基)腺嘌呤(VIIIc)、9-(2-脱氧-4-C-羟甲基-α-L-threo-戊糖基)(IXc)和9-(3-脱氧-4-C-羟甲基-α-L-threo-戊糖基)(Xc)。通过乙酰化VIIIa得到9-(2,5-二-O-乙酰基-4-C-乙酰氧甲基-2-溴-2-脱氧-α-L-阿拉伯呋喃糖基)(VIIId),经过Cu/Zn偶联还原消除和随后的去乙酰化,得到9-(2,3-二脱氧-4-C-羟甲基-α-L-glycero-pent-2-enofuranosyl)腺嘌呤(XIb)。通过VIIId的催化氢化,随后去乙酰化,或者通过XIb的双脱氢衍生物的催化氢化,得到9-(2,3-二脱氧-4-C-羟甲基-α-L-glycero-pentofuranosyl)腺嘌呤(XIIb)。合成的核苷类化合物被用于抗病毒活性测试。