Enzymatic and Organocatalyzed Asymmetric Aldolization Reactions for the Synthesis of Thiosugar Scaffolds
作者:Johan Fanton、Flora Camps、José A. Castillo、Christine Guérard-Hélaine、Marielle Lemaire、Franck Charmantray、Laurence Hecquet
DOI:10.1002/ejoc.201101137
日期:2012.1
We studied the synthesis of original thiosugar scaffolds by enantioselective aldolization. L-Proline-catalyzed C-C bond formation was the key step in the synthesis of L-erythro-thioketoses (3S,4R), whereas fructose-6-phosphate aldolase-catalyzed reactions yielded the D-threo-thioketose series (3S,4S). By the organocatalytic approach, 5-thio-L-ribulofuranose (1) and 5-deoxy-6-thio-L-psicopyranose (2)
我们通过对映选择性醛醇化研究了原始硫糖支架的合成。L-脯氨酸催化的 CC 键形成是合成 L-赤型硫酮糖 (3S, 4R) 的关键步骤,而 6-磷酸果糖醛缩酶催化的反应产生 D-苏式硫酮糖系列 (3S, 4S) . 通过有机催化方法,5-硫代-L-呋喃核糖(1)和5-脱氧-6-硫代-L-吡喃吡喃糖(2)以令人满意的总产率从2-卤代乙醛中获得,而5-硫代-D-木酮呋喃糖( 3) 以 50% 的总产率通过酶促醛醇化反应从相同的起始材料仅两步合成。