The Cephalostatins. 21. Synthesis of Bis-steroidal Pyrazine Rhamnosides
作者:George R. Pettit、Ricardo F. Mendonça、John C. Knight、Robin K. Pettit
DOI:10.1021/np200411p
日期:2011.9.23
The synthesis of bis-steroidal pyrazines derived from 3-oxo-11,21-dihydroxypregna-4,17(20)-diene (4) and glycosylation of a D-ring side chain with α-l-rhamnose have been summarized. Rearrangement of steroidal pyrazine 10 to 14 was found to occur with boron triflouride etherate. Glycosylation of pyrazine 10 using 2,3,4-tri-O-acetyl-α-l-rhamnose iodide led to 1,2-orthoester-α-l-rhamnose pyrazine 17b
已经总结了衍生自 3-oxo-11,21-dihydroxypregna-4,17(20)-diene ( 4 )的双甾体吡嗪的合成和 D 环侧链与 α- 1-鼠李糖的糖基化。发现甾体吡嗪10至14 的重排与三氟化硼醚合物一起发生。使用 2,3,4-三-O-乙酰基-α- 1-鼠李糖碘化物对吡嗪10进行糖基化生成 1,2-原酸酯-α- 1-鼠李糖吡嗪17b。通过使用全甲硅烷基化的α- 1-鼠李糖碘化物作为供体,避免了原酸酯的形成。双甾体吡嗪10和鼠李糖苷17b发现21c和21c在鼠和人癌细胞系组中显着抑制癌细胞生长。吡嗪9抑制了医院病原体粪肠球菌的生长。