A convergent route is described to the super-potent 1D-myo-inositol 1,4,5-trisphosphate receptor agonist adenophostin A (2) and analogues 5 and 7, in which the glucose bisphosphate unit is replaced by corresponding xylose bisphosphate and mannose bisphosphate units respectively. Adenosine was converted into its 2′,3′-O-p-methoxybenzylidene derivative 8ab, which was selectively N6-dimethoxytritylated by a transient protection method. 5′-O-Benzylation followed by reductive acetal cleavage gave, after separation from its 3′-O-p-methoxybenzyl isomer, the versatile glycosyl acceptor 5′-O-benzyl-N6-dimethoxytrityl-2′-O-p-methoxybenzyladenosine 13. Coupling of 13 with selectively protected glucopyranosyl, xylopyranosyl or mannopyranosyl dimethyl phosphites gave the required 3′-O-α-pyranosyl adenosine derivatives. Acidic hydrolysis gave corresponding N6-unprotected triols which were phosphitylated using bis(benzyloxy)(diisopropylamino)phosphine and imidazolium triflate without further N6-protection. Deprotection gave the target trisphosphates 2, 5 and 7. Synthetic adenophostin A (2) was identical with a sample of natural material in all respects. Analogues 5 and 7 will be useful for structure–activity studies on the adenophostins.
描述了超强效 1D-肌醇 1,4,5-
三磷酸受体激动剂腺
磷蛋白 A (2) 以及类似物 5 和 7 的收敛途径,其中
葡萄糖二
磷酸单元被相应的
木糖二
磷酸和
甘露糖二
磷酸取代分别为单位。
腺苷转化为其2',3'-O-对甲氧基亚苯亚甲基衍
生物8ab,并通过瞬时保护方法选择性地N6-二甲氧基三苯甲基化。 5'-O-苄基化,然后还原
缩醛裂解,在与 3'-O-对甲氧基苄基异构体分离后,得到多功能糖基受体 5'-O-苄基-N6-二甲氧基三苯甲基-2'-O-对甲氧基苄基
腺苷 13。 13 具有选择性保护的
吡喃
葡萄糖基、
吡喃
木糖基或
吡喃
甘露糖基
亚磷酸二甲酯得到所需的3'-O-α-
吡喃糖基
腺苷衍
生物。酸性
水解得到相应的N6-未保护的三醇,将其使用双(苄氧基)(二异丙
氨基)膦和
三氟甲磺酸咪唑鎓进行
亚磷酸化,无需进一步的N6-保护。脱保护得到目标
三磷酸2、5和7。合成的
腺苷磷汀A (2)在所有方面与天然材料样品相同。类似物 5 和 7 可用于
腺苷磷酸酯的结构-活性研究。