Synthesis of 10,11-Dihydroleukotriene B<sub>4</sub> Metabolites via a Nickel-Catalyzed Coupling Reaction of <i>cis</i>-Bromides and <i>trans</i>-Alkenyl Borates
作者:Yuji Nakayama、G. Biju Kumar、Yuichi Kobayashi
DOI:10.1021/jo9913199
日期:2000.2.1
corresponding diethyl boronates, which upon ligand exchange with Me(2)C(CH(2)OH)(2) furnished boronate esters 11a and 11b in 75% and 77% yields, respectively. In a similar manner, racemic boronate ester rac-11a, an intermediate for synthesis of 5, was prepared from racemic epichlorohydrin. For synthesis of 2, borate 25 was generated from 11a (1.5 equiv) and MeLi (1.6 equiv). Without isolation, 25 was submitted
10,11-dihydro-,10,11,14,15-tetrahydro-和10,11-dihydro-12-oxoleukotriene B(4)化合物(2,4,5)的合成是通过使用镍-反应路线1中所示的催化偶合反应。C(1)-C(7)片段,TBS醚10a用于2和4,乙氧基乙基(EE)醚10b用于对映体纯形式(> 99%ee),通过修改后的文献程序(参考文献11a)。另一方面,分别由99%ee的(R)-表氯醇(18)合成分别对应于2和4的C(8)-C(20)部分的硼酸酯11a和11b。简而言之,将18通过LiC三键CC(5)H(11)/ BF(3).OEt(2)或C(7)H(15)MgBr / CuCN的环氧化物开环转化为乙炔24和32。将这些乙炔与(+)-(Ipc)(2)BH氢硼化,然后与MeCHO反应,得到相应的硼酸二乙酯,在与Me(2)C(CH(2)OH)(2)进行配体交换后,提