Indium-Promoted Acyloxyallylation Reaction of Azetidine-2,3-diones in Aqueous Media: A New Route to Densely Functionalized 3-Substituted 3-Hydroxy-β-lactams
作者:Benito Alcaide、Pedro Almendros、Cristina Aragoncillo、Gema Cabrero、Ricardo Callejo、M. Pilar Ruiz
DOI:10.1002/ejoc.200800521
日期:2008.9
Densely functionalized 3-substituted 3-hydroxy-β-lactams have been obtained by acyloxyallylation reaction of azetidine-2,3-diones with 3-bromopropenyl acetate or benzoate in aqueous media promoted by indium under Barbier conditions. Two new stereocenters were formed; the stereochemistry at the new C-3 quaternary center was fully controlled by placing a bulky chiral substituent at C-4. However, poor
在巴比尔条件下,通过氮杂环丁烷-2,3-二酮与乙酸3-溴丙烯酯或苯甲酸酯在铟促进的水性介质中的酰氧基烯丙基化反应,得到了密集官能化的3-羟基-β-内酰胺。形成了两个新的立体中心;通过在 C-4 上放置一个庞大的手性取代基,可以完全控制新 C-3 四元中心的立体化学。然而,在形成的新烯丙基立体中心中观察到较差的非对映选择性(高达 58 % de)。(© Wiley-VCH Verlag GmbH & Co. KGaA,69451 Weinheim,德国,2008)