Total Synthesis of Pumiliotoxins 209F and 251D via Late-Stage, Nickel-Catalyzed Epoxide−Alkyne Reductive Cyclization
作者:Katrina S. Woodin、Timothy F. Jamison
DOI:10.1021/jo071132e
日期:2007.9.1
Pumiliotoxins 209F and 251D were synthesized using highly selective nickel-catalyzed epoxide−alkyne reductive cyclizations as the final step. The exocyclic (Z)-alkene found in the majority of the pumiliotoxins was formed stereospecifically and regioselectively, without the use of a directing group on the alkyne, and the epoxide underwent ring opening exclusively at the less hindered carbon to provide
铝毒素209F和251D使用高度选择性的镍催化环氧化物炔还原环化反应作为最终步骤合成。在大多数pumiliotoxins毒素中发现的环外(Z)烯烃是立体定向和区域选择性形成的,无需在炔烃上使用导向基团,并且环氧化物仅在受阻较小的碳上开环以提供所需的叔醇。使用非对映选择性地将sulf代氧鎓阴离子加到脯氨酸衍生的甲基酮中来制备环氧化物。