Synthesis of C-nucleosides by ring transformation of 1,3-oxazine derivatives.
作者:NOBUYA KATAGIRI、NOBUAKI TABEI、SHUGO ATSUUMI、TORU HANEDA、TETSUZO KATO
DOI:10.1248/cpb.33.102
日期:——
Treatment of the β-D-ribofuranosyl cyanide 5 with sodium methoxide, followed by reaction with diketene, gave the spiro 1, 3-oxazine 6, which underwent the ring transformation with ammonia and phenylhydrazine to give the protected pyrimidine (8) and 1, 2, 4-triazole (13) C-nucleosides, respectively. Deprotection of 8 with 90% trifluoroacetic acid gave the pyrimidine C-nucleoside 9. Passage of hydrogen chloride gas over a solution of the cyanide 1 and benzyl hydrosulfide gave the fully protected ribofuranosylthioformimidate 15. Treatment of 15 with triethylamine, followed by reaction with diketene gave the dihydrofuran derivative 16. Compound 16, on treatment with ammonia, hydroxylamine, and phenylhydrazine, was transformed into the corresponding furan derivatives 17-19.
β-D-呋喃核糖氰化物5在甲醇钠处理后,与双乙烯酮反应,得到螺1,3-恶嗪6,该化合物在氨和苯肼的作用下分别转化为保护的嘧啶(8)和1,2,4-三唑C-核苷13。用90%三氟乙酸脱保护8得到嘧啶C-核苷9。氰化物1与苄基硫醇氢化物的溶液在氯化氢气体作用下得到完全保护的呋喃核糖硫代甲亚胺酸酯15。15在三乙胺处理后,与双乙烯酮反应得到二氢呋喃衍生物16。化合物16在氨、羟胺和苯肼的作用下分别转化为相应的呋喃衍生物17-19。