title compound 1a was prepared from cyclopentadienylthallium in 11 steps. The key component of the pseudo-disaccharide 1a, (−)-allosamizoline 2, was synthesized in 2 steps starting from the known cyclopentene 4 by formation of the aminoimidate 5 followed by a mercury(II)trifluoroacetate mediated cyclization and radical oxygenation. Regioselective and stereospecific coupling of 6-O-benzyl-(−)-allosamizoline8
由
环戊二烯基th以11个步骤制备标题化合物1a。假二糖1a的关键成分(-)-allosamizoline 2从已知的
环戊烯4开始,分两步合成
氨基亚
氨酸酯5,然后形成
三氟乙酸汞(II)介导的环化和自由基氧合。6- O-苄基-(-)-allosamizoline 8与
恶唑啉糖基供体11的区域选择性和立体定向偶联以及随后的脱保护提供了β-1,4-伪二糖1a。