A short, formal, biomimetic synthesis of (+/-)-polygalolides A and B.
A short, formal, biomimetic synthesis of (+/-)-polygalolides A and B.
复制标题
DOI：
10.1021/ol0630898
复制
发表时间：
2007-02
期刊：
影响因子：
5.2
通讯作者：
B. Snider;Xiaoxing Wu;Seiichi Nakamura;S. Hashimoto*
中科院分区：
文献类型：
--
作者：
B. Snider;Xiaoxing Wu;Seiichi Nakamura;S. Hashimoto*
[反应：双乙酰氧基吡喃酮9与Et 3 N反应得到3-氧化吡喃鎓叶立德10，其与α-亚甲基丁内酯进行立体和区域特异性[5 + 2]环加成得到16（34%）。用Cs2 CO 3处理16导致内酯和乙酸酯的水解以及羟乙基基团与烯酮的共轭加成。酸化后内酯化得到4（57%），完成了远志内酯A和B的两步形式合成。
[reaction: see text] Reaction of bisacetoxy pyranone 9 with Et3N gave 3-oxidopyrylium ylide 10, which underwent a stereo- and regiospecific [5 + 2] cycloaddition with alpha-methylenebutyrolactone to afford 16 (34%). Treatment of 16 with Cs2CO3 resulted in hydrolysis of the lactone and acetate and conjugate addition of the hydroxyethyl group to the enone. Lactonization on acidification afforded 4 (57%), completing a two-step, formal synthesis of polygalolides A and B.