作者:Subhasish Purkayastha、Raymond P. Panzica
DOI:10.1002/jhet.5570270350
日期:1990.3
β-D-Arabinofurano[1′,2′:4,5]oxazolo-s-triazin-4-one-6-thione (7b) and its t-butyldimethylsilyl protected counterpart 7a were synthesized by treating the appropriate 2-amino-β-D-arabinofurano[1′,2′:4,5]-2-oxazoline with ethoxycarbonyl isothiocyanate. These 2,2′-anhydro-s-triazine nucleosides were then subjected to alkylation under similar reaction conditions. Alkylation of 3′,5′-bis(O-t-butyldimeth
β-d阿糖呋喃并[1',2':4,5] oxazolo-小号三嗪-4-酮-6-硫酮(7B)及其吨丁基二保护的对应图7a是通过处理相应的2-氨基-合成β-D-阿拉伯呋喃酮[1',2':4,5] -2-恶唑啉与乙氧羰基异硫氰酸酯。这些2,2'-脱水-小号然后嗪核苷类似的反应条件下进行烷基化。的3烷基化',5'-双(OT丁基二)-β-d阿糖呋喃并[1',2': - 4,5] oxazolo-小号三嗪-4-酮-6-硫酮(7A)中提供的靶向的S-烷基化核苷,即C6-SCH 3(9a),C6-SCH 2 -CH = CH 2(10a)和C6-S-CH 2 -C = CH(11a),产率合理。尝试将这些核苷脱保护失败。为了避免该问题,用相同的试剂将7b烷基化。在每种情况下的,而不是预期的S-烷基化的脱水核苷,5-的混合物Ñ -alkylanhydro-小号和5-三嗪-4,6-二酮Ñ -alkylanhy