Improved asymmetric total synthesis of corticoids via biomimetic polyene cyclization methodology
Improved asymmetric total synthesis of corticoids via biomimetic polyene cyclization methodology
复制标题
通过仿生多烯环化方法改进皮质激素的不对称全合成
DOI：
10.1021/jo00320a062
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发表时间：
1981
影响因子：
3.6
通讯作者：
A. Gopalan
中科院分区：
文献类型：
--
作者：
W. S. Johnson;B. Frei;A. Gopalan
与Mukaiyama手性配体络合的（三甲基硅基）乙炔锂（8）在-120 ℃下加成到醛3上，以70%的产率和90%ee得到醇9，醇9是生成环化底物1的中间体，经2生成皮质激素。提供更高光学产率的更实用的方法涉及使用新试剂12来生产乙炔酮，即12-*· 14-*·15。减少15个，
Addition of lithium (trimethylsilyl) acetylide (8), complexed with the Mukaiyama chiral ligand, to the aldehyde 3 at-120 C gave, in 70% yield and90% ee, the alcohol 9 which is an intermediate for producing the cy-clization substrate 1 leading (via 2) to corticoids. A more practical approach which affords higher optical yields in-volves the use of a new reagent 12 for producing an ace-tylenic ketone, ie, 12-*· 14-» 15. Reduction of 15 by the