Use of lithium (α-methylbenzyl)allylamide for a formal asymmetric synthesis of thienamycin
作者:Stephen G. Davies、David R. Fenwick
DOI:10.1039/a700216e
日期:——
The highly stereoselective conjugate addition of lithium
(αR)-(α-methylbenzyl)allylamide 3 to
(E)-tert-butyl penta-2,4-dienoate 4, followed by a
stereoselective aldol reaction with acetaldehyde, are the key steps in the
synthesis of the known β-lactam intermediate,
(3S,4R)-3-[(R)-1-(tert-butyldimethyls
ilyloxy)ethyl]-4-vinylazetidin-2-one 2, for elaboration to thienamycin and
its derivatives.
(δ±R)-(δ-甲基苄基)烯丙基酰胺锂 3 与 (E)-2,4- 二烯酸叔丁酯 4 的高度立体选择性共轭加成,然后与乙醛发生立体选择性醛醇反应、这是合成已知δ-内酰胺中间体--(3S,4R)-3-[(R)-1-(叔丁基二甲基硅氧基)乙基]-4-乙烯基氮杂环丁烷-2-酮 2 的关键步骤,可用于制备噻那霉素及其衍生物。