A short asymmetric synthesis of methyl 2-((1S,3R)-3-((tert-butyldiphenylsilyl)oxy)cyclopentyl)acetate from norbornene
作者:Buwen Huang、Jeff Elleraas、Jason Ewanicki、Scott C. Sutton
DOI:10.1016/j.tetlet.2020.152057
日期:2020.7
Methyl 2-((1S,3R)-3-((tert-butyldiphenylsilyl)oxy)cyclopentyl)acetate has been synthesized from norbornene using Hayashi’s (S)-MOP Pd-catalyzed asymmetric hydrosilation. On a 1 mol scale, asymmetric hydrosilation of norbornene afforded an 84:16 exo- to endo-norborneol mixture but with exclusive 1R,4S-stereochemistry at the bridgehead carbons. The norborneol mixture was converted to an optically pure
使用Hayashi's(S)-MOP Pd催化的不对称硅氢化反应,由降冰片烯合成了2-((1 S,3 R)-3-((叔丁基二苯基甲硅烷基)氧基)环戊基)乙酸甲酯。在1 mol的规模上,降冰片烯的不对称硅氢化作用提供了84:16的内降冰片醇的内-外混合物,但在桥头碳上仅具有1 R,4 S-立体化学。通过高产率串联氧化/ Baeyer-Villiger反应将降冰片醇混合物转化为光学纯的手性双环内酯。酸促进内酯的开环,然后立即进行甲硅烷基保护,得到手性顺式五个步骤中的-1,3-环戊烷中间体,总产率为41%。