Koo Bonsuk, McDonald Frank E
Department of Chemistry, Emory University, Atlanta, GA 30322, USA.
Org Lett. 2005 Aug 18;7(17):3621-4. doi: 10.1021/ol050975u.
Tungsten-catalyzed cycloisomerization of alkynyl alcohols including 8 provides only the endocyclic enol ether (11) as a key intermediate for the branched C-glycoside substructure (2) of altromycin B. A sequence of Stille cross-coupling reaction and regio- and stereoselective functional group transformations affords each C13-diastereomer of the branched C-arylglycoside (2a and 2b). [reaction: see text]
钨催化包括8在内的炔醇的环异构化反应,仅生成内环烯醇醚(11)作为阿洛霉素B支链C-糖苷亚结构(2)的关键中间体。通过一系列的Stille交叉偶联反应以及区域和立体选择性官能团转化反应,可得到支链C-芳基糖苷(2a和2b)的每个C13-非对映异构体。[反应:见正文]