Hydrolytic Reactions of thecis-Methyl Ester of 3′-Deoxy-3′-thiothymidine 3′,5′-Cyclic(phosphorothiolate)
作者:Mohamed I. Elzagheid、Kati Mattila、Mikko Oivanen、Bryan C. N. M. Jones、Richard Cosstick、Harri Lönnberg
DOI:10.1002/(sici)1099-0690(200005)2000:10<1987::aid-ejoc1987>3.0.co;2-x
日期:2000.5
pH-independent reaction is suggested to take place by attack of a water molecule on the carbon atom and concomitant C−O bond rupture, whereas the alkaline and acidic reactions involve attack of the nucleophile on the phosphorus atom and formation of a pseudorotating thiophosphorane intermediate. Under acidic conditions, cleavage of the N-glycosidic linkage competes with the phosphoester hydrolysis, corresponding
3'-脱氧-3'-硫代胸苷 3'-S,5'-O-环(硫代磷酸酯)(1a)的顺式甲酯的水解,随后进行了 HPLC 和 MS。在 pH 5 时为氢氧根离子。未催化和酸催化的反应分别以 9:1 和 1:3 的摩尔比生成两种硫代磷酸二酯,即 3'-S,5'-O-环硫代磷酸酯 2 和 3'-S-硫代磷酸酯甲酯 3 . 氢氧根离子催化反应产生摩尔比为 1:2 的内环 P-O 和 P-S 键断裂产物(分别为 3 和 4)。建议通过水分子对碳原子的攻击和伴随的 C-O 键断裂来进行不依赖于 pH 的反应,而碱性和酸性反应涉及亲核试剂对磷原子的攻击和拟旋转硫代正膦中间体的形成. 在酸性条件下,