Disclosed are O-protected compounds of the formula (I):
wherein B is an optionally protected nucleobase, and R1-R3 are as described herein, wherein at least one of R1-R3 is —CH2—O—N═CHR. The compounds are useful as intermediates in oligonucleotide synthesis. Also disclosed is a method of preparing the compounds from nucleosides via a process comprising conversion of a hydroxyl group to a methylthiomethoxy group, and a method of preparing oligonucleotides such as RNA starting from the compounds. The —CH2—O—N═CHR group is stable during oligonucleotide synthesis and can be easily removed after synthesis via, for example, treatment with a base.
本发明公开了式(I)的O-保护化合物:
其中B是可选择保护的核苷碱,R1-R3如本文所述,其中至少一个R1-R3为—
CH2—O—N═CHR。该化合物在寡核苷酸合成中作为中间体有用。本发明还公开了一种从核苷通过将羟基转化为甲
硫甲氧基基团制备该化合物的方法,以及一种从该化合物开始制备RNA等寡核苷酸的方法。— —O—N═CHR基团在寡核苷酸合成过程中是稳定的,可以通过例如碱处理等方法在合成后轻松去除。