Synthesis of β-hydroxy-δ-trichloromethyl-δ-valerolactones by intramolecular samarium/ytterbium diiodide-mediated Reformatsky reaction
作者:Thies M. Schulze、Jörg Grunenberg、Stefan Schulz
DOI:10.1016/j.tetlet.2012.11.146
日期:2013.2
intramolecular Reformatsky reaction. The cyclisation was effected by samarium diiodide or (for the first time) ytterbium diiodide. The diastereoselectivity of the reaction corresponds to earlier investigations by Molander. Consecutive stereoselective reactions during the esterification to the Reformatsky precursor 1,1,1-trichloropent-4-en-2-yl 2-bromopropanoate and in the Reformatsky reaction itself led
α甲基β羟基δ三氯甲基的合成- δ戊内酯是通过分子内的Reformatsky反应来实现的。通过二碘化sa或(首次)二碘化effect实现环化。反应的非对映选择性对应于Molander较早的研究。在酯化为Reformatsky前体1,1,1-三氯戊-4- en-2-基2-溴丙酸酯期间发生的连续立体选择反应以及在Reformatsky反应本身中导致(3 RS,4 RS,6 SR)-4-羟基-3-甲基-6-(三氯甲基)四氢-2 H-吡喃-2-酮(3a)为主要形成的非对映异构体。讨论了过渡态中取代基的取向的影响。