Total Synthesis of (±)-Herbertenolide by Stereospecific Formation of Vicinal Quaternary Centers in a Crystalline Ketone
作者:Danny Ng、Zhe Yang、Miguel A. Garcia-Garibay
DOI:10.1021/ol0499250
日期:2004.2.1
[reaction: see text] The sesquiterpene (+/-)-herbertenolide was synthesized in seven steps from commercial 2-bromo-4-methylanisole. In the key step, two adjacent stereogenic quaternary centers were controlled by a highly chemoselective and stereospecific photodecarbonylation reaction of crystalline methyl-trans-3-(2-methyl-5-methoxyphenyl)-1,3-dimethyl-2-oxocyclohexancarboxylate (3). An efficient generation
[反应:见正文]倍半萜烯(+/-)-香叶烯内酯是由商业上的2-溴-4-甲基茴香醚分七个步骤合成的。在关键步骤中,两个相邻的立体异构季铵盐中心受到结晶甲基-反式-3-(2-甲基-5-甲氧基苯基)-1,3-二甲基-2-氧代环己羧酸酯的高度化学选择性和立体特异性光脱羰反应的控制(3) 。有效生成自由基对和固态施加的立体化学控制表明该反应可能成为有用的合成方法。