Inverse Phosphotriester DNA Synthesis Using Photochemically-Removable Dimethoxybenzoin Phosphate Protecting Groups
摘要:
A method has been developed to prepare short DNA sequences using light to deprotect a nucleoside 3'-phosphotriester, generating a phosphodiester useful for coupling with a free 5'-OH-nucleotide. The dimethoxybenzoin group is used as the photochemically-removable protecting group for the 3'-phosphate. Cyanoethyl is most effective as the second protecting group on the phosphodiester. Because the method is directed at the preparation and use of the DNA sequences while still bound to the support, allyl and allyloxycarbonyl protecting groups are used for the nitrogenous bases since, based on the work of Hayakawa and Noyori, they can be removed without cleaving the DNA from the support. Two simple trinucleotides have been prepared in solution using this method. It has been demonstrated that the photochemical deprotection conditions do not lead to the formation of cyclobutane dimers from adjacent T residues.
摘要 5′- O -{[双(4-甲氧基苯基)(苯基)甲基])-2′-脱氧-3′-硫代肌苷和其S-磷硫代酰胺分别由市售的2′-制备。脱氧肌苷。关键的3'-硫代中间体是通过两个连续的构型反转合成的:一锅氧化/还原反应和S N 2反应。该中间体易于以高收率转化为目标化合物。与其他方法相比,该合成策略的优点是反应步骤短,总收率相对较高以及构型转化的区域选择性。该产物可用作制备新的功能化核苷的中间体。 5′- O -{[双(4-甲氧基苯基)(苯基)甲基])-2′-脱氧-3′-硫代肌苷和其S-磷硫代酰胺分别由市售的2′-制备。脱氧肌苷。关键的3'-硫代中间体是通过两个连续的构型反转合成的:一锅氧化/还原反应和S N 2反应。该中间体易于以高收率转化为目标化合物。与其他方法相比,该合成策略的优点是反应步骤短,总收率相对较高以及构型转化的区域选择性。该产物可用作制备新的功能化核苷的中间体。