D-Eritadenine (Ia) and L-eritadenine (IIa) were prepared from 5-(adenin-9-yl)-5-deoxyaldofuranoses or enantiomeric 2,3-disubstituted erythronolactones (VIIIb, c, XIV). Oxidation of methyl 2,3-O-isopropylidene-D-ribofuranoside (IX) with periodate in the presence of ruthenium, followed by acid hydrolysis and reduction with sodium borohydride, afforded L-ribonolactone (XI). Its 2,3-O-isopropylidene derivative was subjected to alkaline hydrolysis, followed by oxidation with periodate, reduction with sodium borohydride and reaction with cyclohexanone to give 2,3-O-cyclohexylidene-L-erythronolactone (XIV). Condensation of [U-14C]-adenine with VIIIb, followed by acid hydrolysis, afforded [U-14C-adenine]-D-eritadenine. The threo-eritadenines III and IV were prepared by oxidation of 1-(adenin-9-yl)-1-deoxy-2,3-O-isopropylidenethreitols XVI and XVII with sodium periodate in the presence of ruthenium, followed by acid hydrolysis. Reaction of 9-(2,2-diethoxyethyl)adenine (XIX) with malonic acid gave 4-(adenin-9-yl)-3-butenoic acid (XXI); its methyl ester XXII, prepared by treatment with methanol, was isomerized with triethylamine to give methyl 4-(adenin-9-yl)-2-butenoate (XXIII). Hydroxylation of XXIII with osmium tetroxide afforded the racemic mixture of D- and L-threo-eritadenine (III+ IV). Eritadenines Ia and IIa were active against vaccinia, measles and vesicular stomatitis virus. Eritadenine Ia was also effective against reo- and parainfluenza virus. In general, the antiviral activity of the eritadenines decreased in the order D-erythro (Ia) > L-erythro (IIa) > D- and L-threo (III, IV).
D-厄利他
呋喃核苷(Ia)和L-厄利他
呋喃核苷(IIa)是从5-(
腺嘌呤-9-基)-5-
脱氧醛糖或对映异构的2,3-二取代的赤霉糖内
酯(VIIIb, c, XIV)制备而成。使用高
碘酸盐在
钌的存在下
氧化
甲基2,3-O-
异丙基-
D-核糖呋喃苷(IX),随后进行酸
水解和
硼氢化钠还原,得到
L-核糖内
酮(XI)。将其2,3-O-
异丙基衍
生物经过碱
水解,随后经过高
碘酸盐氧化、
硼氢化钠还原和与
环己酮反应,得到2,3-O-
环己基-L-赤霉糖内
酯(XIV)。[U-14C]-
腺嘌呤与VIIIb缩合,经过酸
水解,得到[U-14C-
腺嘌呤]-D-厄利他
呋喃核苷。通过高
碘酸盐在
钌的存在下
氧化1-(
腺嘌呤-9-基)-1-
脱氧-2,3-O-
异丙基脱氢醇(XVI)和(XVII),得到threo-厄利他
呋喃核苷III和IV。9-(
2,2-二乙
氧基乙基)
腺嘌呤(XIX)与
丙二酸反应,得到4-(
腺嘌呤-9-基)-3-
丁烯酸(XXI);经过
甲醇处理制备其甲
酯(XXII),再与
三乙胺异构化,得到
甲基4-(
腺嘌呤-9-基)-
2-丁烯酸
酯(XXIII)。XXIII的羟化反
应得到D-和L-厄利他
呋喃核苷的外消旋混合物(III+IV)。厄利他
呋喃核苷Ia和IIa对牛痘病毒、麻疹病毒和
水疱性口炎病毒具有活性。厄利他
呋喃核苷Ia也对副流感病毒和副流感病毒有效。总体而言,厄利他
呋喃核苷的抗病毒活性按照D-赤霉糖(Ia) > L-赤霉糖(IIa) > D-和L-threo(III, IV)的顺序递减。