Cheong Paul Ha-Yeon, Yun Heedong, Danishefsky Samuel J, Houk K N
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
Org Lett. 2006 Apr 13;8(8):1513-6. doi: 10.1021/ol052862g.
[reaction: see text] The stereoselectivity of the key epoxidation step in the synthesis of guanacastepene A is shown to be controlled by torsional steering. In this particular epoxidation reaction, the transition structure energetic difference is enhanced by the great asynchronicity of the forming C-O bonds that intensifies the torsional interactions.
[反应:见正文] 已表明,在合成瓜纳卡斯特烯A的关键环氧化步骤中,立体选择性受扭转导向控制。在这个特定的环氧化反应中,由于形成的C-O键的高度异步性增强了扭转相互作用,从而增大了过渡结构的能量差。