申请人:Exiqon A/S
公开号:US06734291B2
公开(公告)日:2004-05-11
A synthesis of [2.2.1]bicyclo nucleosides which is shorter and provides higher overall yields proceeds via the key intermediate of the general formula III, wherein R4 and R5 are, for instance, sulfonates and R7 is, for instance, a halogen or an acetate. From compounds of the general formula II, such as 3-O-aryl-4-C-hydroxymethyl-1,2-O-isopropylidene-&agr;-D-ribofuranose, intermediates of the general formula III are suitable for coupling with silylated nucleobases. Upon one-pot base-induced ring-closure and desulfonation of the formed [2.2.1]bicyclo nucleoside, a short route to each the LNA (Locked Nucleic Acid) derivatives of adenosine, cytosine, uridine, thymidine and guanidine is demonstrated. The use of the 5′-sulfonated ring-closed intermediate also allows for synthesis of 5′-amino- and thio-LNAs
一种合成[2.2.1]双环核苷的方法,该方法更短且提供更高的总收率,通过通式III的关键中间体进行,其中R4和R5例如是磺酸盐,R7例如是卤素或乙酸。从通式II的化合物,例如3-O-芳基-4-C-羟甲基-1,2-O-异丙基亚-D-核糖,通式III的中间体适合与硅化核碱基偶联。通过一锅法碱诱导的环闭合和去磺酸化形成[2.2.1]双环核苷后,演示了腺嘌呤、胞嘧啶、尿嘧啶、胸腺嘧啶和鸟嘌呤的LNA(锁定核酸)衍生物的短路线。使用5'-磺酸化的环闭合中间体还允许合成5'-氨基和硫代LNAs。