Enantioselective synthesis of bicylco[3.2.1]octan-8-ones using a tandem Michael-Henry reaction.
Bicyclo[3.2.1]octan-8-ones have been prepared from a tandem Michael-Henry reaction between cyclohexane-1,2-diones and nitroalkenes using a quinine-derived thiourea as the catalyst. Although four stereogenic centers were created during the reaction, only two diastereomers were obtained in good diastereoselectivity and high enantioselectivity (92-99% ee). When 3-methylcyclohexane-1,2-dione (R(1) = Me) was used as the substrate, only the regioisomeric product of the corresponding thermodynamic enolate was obtained.
Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, Texas 78249-0698, USA.
Derong
D
Ding
Cong-Gui
CG
Zhao
Qunsheng
Q
Guo
Hadi
H
Arman