Norbornanoid Chiral Ketones by Desymmetrization of Dibromoalkenes
作者:Ramazan Koçak、Giuseppe Borsato、Ottorino De Lucchi、Arif Daştan
DOI:10.1002/hlca.201300191
日期:2014.4
New optically active polycyclic ketones 6a–6d, amenable to a large variety of synthetic applications, have been prepared from readily available 2,3‐dibromonorbornene and analogs (Scheme 2) via desymmetrization with (−)‐ephedrine, followed by hydrolysis under mild acidic conditions. At variance with substrates 4a–4d, the sterically hindered norbornene derivative 4e reacts with the solvent N‐methylpyrrolidin‐2‐one