Treatment of the purified 5′-aldehyde (2a) (derived from 6-N-benzoyl-2′,3′-O-isopropylideneadenosine (1a)) with methylenetriphenylphosphorane and successive deprotection with ammonia and acid gave 9-(5,6-dideoxy-β-D-ribo-hex-5-enofuranosyl)adenine (5′-deoxy-5′-methyleneadenosine) (4). Oxidation of 1a or 2′,3′-O-isopropylideneadenosine (1b) and treatment of the crude 5′-aldehydes (2a or 2b) with (p-toluenesulfonylmethylene)triphenylphosphorane gave high yields of the 5′-deoxy-5′-tosylmethylene derivatives (5a or 5b). Removal of the tosyl group from 5b to give 3b was effected with tributylstannyllithium, but sulfone cleavage by the usual reductive methods failed. Reduction and deprotection of 5a or 5b gave 9-[5,6-dideoxy-6-(p-toluenesulfonyl)-β-D-ribo-hexofuranosyl]adenine (6b). Isomerization of the vinyl tosyl (5b) to a 4′,5′-unsaturated allylic tosyl derivative (7) occurred under cleavage conditions and in solutions of aqueous or organic bases. Key words: adenosine, 5′-deoxyadenosine, 5′-methylene-5′-deoxyadenosine, nucleosides.
经过纯化的5'-醛(2a)(来源于6-N-苯甲酰基-2',3'-O-异丙基脱氧腺苷(1a))与三苯基膦甲烷反应,然后用氨水和酸进行连续脱保护,得到9-(5,6-二脱氧-β-D-核糖-己-5-烯基呋喃核苷)腺嘌呤(5'-脱氧-5'-亚甲基腺苷)(4)。氧化1a或2',3'-O-异丙基腺苷(1b),然后用(p-甲苯磺酰亚甲基)三苯基膦烷处理粗的5'-醛(2a或2b),得到5'-脱氧-5'-对甲苯磺酰亚甲基衍生物(5a或5b)的高产率。用三丁基锡基锂去除5b中的对甲苯磺酰基,但通常还原方法下的磺酰基裂解失败。还原和脱保护5a或5b得到9-[5,6-二脱氧-6-(对甲苯磺酰基)-β-D-核糖-己呋喃核苷]腺嘌呤(6b)。乙烯基对甲苯磺酰基(5b)在裂解条件下或水溶液或有机碱溶液中发生异构化,形成4',5'-不饱和联苯基对甲苯磺酰基衍生物(7)。关键词:腺苷,5'-脱氧腺苷,5'-亚甲基-5'-脱氧腺苷,核苷。