作者:Martin J. Wanner、Gerrit-Jan Koomen
DOI:10.1039/b102897a
日期:——
A series of new 2-substituted adenosine derivatives was synthesised via addition and condensation reactions with 2-nitrosoadenosine triacetate 4. The exceptional reactivity of the adenosine nitroso functionality was demonstrated by reaction with, e.g., dienes (4 + 2 cycloaddition), cyclohexene (‘ene’ reaction), furans (addition/rearrangement) and with anilines (Mills coupling). 2-Nitrosoadenosine triacetate was prepared from 6-chloropurine riboside triacetate via nitration at the 2-position followed by reduction/oxidation of the nitro group. The vulnerable nitroso functionality of 4 had to be protected by 4 + 2 cycloaddition with cyclopentadiene to make deacylation of the ribose ring possible. Retro-Diels–Alder reaction of the deacylated product at 95 °C gave the title compound 2-nitrosoadenosine 7. Dimerisation of the nitroso functionality of triacetate 4 was studied with 1H NMR by changing the temperature, concentration and solvent. In particular, variation of temperature gave control over this dimerisation: 100% monomer at 65 °C gave complete dimerisation at −20 °C.
一系列新的2取代腺苷衍生物是通过与2-亚硝基腺苷三乙酸酯4进行加成和缩合反应合成的。腺苷亚硝基功能团的优异反应性通过与烯烃(4 + 2环加成反应)、环己烯(“烯”反应)、呋喃(加成/重排反应)和苯胺(米尔斯偶联)等反应得到了证明。2-亚硝基腺苷三乙酸酯是通过对6-氯嘌呤核苷三乙酸酯进行2位的硝化反应,然后再对硝基进行还原/氧化反应合成的。4的脆弱亚硝基功能团需要通过与环戊二烯进行4 + 2环加成反应进行保护,以使RNA环的去酰化成为可能。在95°C下,去酰化产物的反向Diels-Alder反应生成了标题化合物2-亚硝基腺苷7。通过改变温度、浓度和溶剂,研究了三乙酸酯4的亚硝基功能团的二聚化过程。特别是,温度的变化对这种二聚化反应起到了控制作用:在65°C时为100%单体,在-20°C时则完全二聚化。