Solid-Phase Synthesis of Oligonucleotide Glycoconjugates Bearing Three Different Glycosyl Groups: Orthogonally Protected Bis(hydroxymethyl)-<i>N,N</i><i>‘</i>-bis(3-hydroxypropyl)malondiamide Phosphoramidite as Key Building Block
作者:Johanna Katajisto、Petri Heinonen、Harri Lönnberg
DOI:10.1021/jo048984o
日期:2004.10.1
O‘-(methoxymethylene)bis(hydroxymethyl)malonate (3) was observed to undergo a stepwise aminolysis when treated with 3-aminopropanol. This allowed convenient preparation of bis(hydroxymethyl)-N,N‘-bis(3-hydroxypropyl)malondiamide bearing orthogonal levulinyl (Lev) and tert-butyldiphenylsilyl (TBDPS) protections at the two N-hydroxypropyl groups (8). One of the hydroxylmethyl functions was then protected with a 4,4‘-dimethoxytrityl
二ø,Ö “ - (甲氧基亚甲基)双(羟甲基)丙二酸二乙酯(3)中观察到当与3-氨基丙醇处理经过逐步氨解。这允许方便地制备在两个N-羟丙基上带有正交乙酰丙酰基(Lev)和叔丁基二苯基甲硅烷基(TBDPS)保护的双(羟甲基)-N,N'-双(3-羟丙基)丙二酰胺(8)。然后将一个羟甲基官能团用4,4'-二甲氧基三苯甲基(DMTr)基团进行保护,然后将另一个进行磷酸化以获得甲基N,N-二异丙基亚氨基膦酸酯(1)。该结构单元用于合成带有三个不同糖单元的寡核苷酸糖缀合物(25和26)。在含有1的序列的常规亚磷酰胺链组装后,除去5'-末端DMTr基团,并偶联合适的糖基6- O-亚磷酰胺基。按Lev和TBDPS的顺序除去支链单元的其余保护基,并使暴露的羟基官能团与所需的糖基6- O-亚磷酰胺基依次反应。通过常规的氨解作用实现了共轭物从载体上的整体脱保护和裂解。