Analogues of Sialic Acids as Potential Sialidase Inhibitors Synthesis of 2-C-Hydroxymethyl Derivatives ofN-Acetyl-6-amino-2,6-dideoxy-neuraminic Acid
作者:Bruno Bernet、A. R. C. Bulusu Murty、Andrea Vasella
DOI:10.1002/hlca.19900730422
日期:1990.6.20
The intramolecular cycloaddition of the previously described azidoalkene 16, the related diacetates 7 and 13, and the monoacetate 8 led diastereoselectivity to the (2R)- and (2S)-configurated hydropyridotriazoles 17, 9 and 11, 14 and 15, and 10 and 12, respectively (Scheme 1). Thermolysis of 16 gave also the aziridine 18, its proportion increasing with reaction time. The diastereoselectivity of the
先前描述的azidoalkene的分子内环16,相关二乙酸酯7和13,和单乙8导致非对映选择性的(2 - [R ) -和(2小号) -构型hydropyridotriazoles 17,9和11,14和15,和10和分别为12(方案1)。热分解16也给了氮丙啶18,其比例随反应时间而增加。环加成的非对映选择性是根据空间相互作用和过渡态的Hbonds合理化的。在苯中的光解将9部分转化为氮丙啶19。用AcOH水溶液处理9得到19和四氢呋喃20,用在苯20中的AcOH和三乙酸酯23,以及在THF中的H 2 SO 4水溶液,伯醇22(室温)或19和22(0°)。脱乙酰化的9然后与吡啶鎓盐酸盐反应,得到四氢呋喃21和氯化物24(方案2)。二乙酸酯22和三乙酸酯23得到三联体25,其被脱保护为26。酮-氮丙啶18(NaBH 4)的还原得到醇27和29,其被乙酰化分别得到28和19(方案3)。用苯中的A