Nucleosides. Part LXIII. Acetals as new 2?-O-protecting functions for the synthesis of oligoribonucleotides: Synthesis of uridine building blocks and evaluation of their relative acid stability
作者:Stefan Matysiak、Hans-Peter Fitznar、Ralf Schnell、Wolfgang Pfleiderer
DOI:10.1002/hlca.19980810557
日期:——
A broad variety of new acyclic vinyl ethers (see 6–41) have been synthesized via the vinyl-interchange reaction of ethyl vinyl ether at room temperature using mercury(II) trifluoroacetate as a highly efficient catalyst. The appropriate vinyl ethers were reacted under acidic conditions with 3′,5′-O-silyl-protected uridine 42 to the corresponding 2′-O-(1-alkoxyethyl) derivatives 43–83 which gave, on
各种各样的新的无环乙烯基醚(见6 - 41)已被合成通过在室温下的乙基乙烯基醚的乙烯基-交换反应使用汞(II)三氟乙酸盐作为一种高效催化剂。适当的乙烯基醚是在酸性条件下反应,用3',5'- ø -甲硅烷保护的尿苷42到相应的2'- ø - (1-烷氧基乙基)衍生物43 - 83这给了,对于F的脱甲硅烷基-离子,高产率的尿苷2'- O-缩醛衍生物84 – 124。使用TLC和HPLC技术确定了新合成化合物在酸性和碱性条件下的相对稳定性。受保护的保护基为寡核糖核苷酸合成提供了最佳性能。有趣的是,β-取代的乙基型的非常酸稳定缩醛118 - 121和123可以由β消去过程中提供了一系列潜在的合成值的碱不稳定的乙缩醛的裂解。