Dynamic Kinetic Resolution of Alkenyl Cyanohydrins Derived from α,β-Unsaturated Aldehydes: Stereoselective Synthesis of <i>E</i>-Tetrasubstituted Olefins
作者:Jadab Majhi、Ben W. H. Turnbull、Ho Ryu、Jiyong Park、Mu-Hyun Baik、P. Andrew Evans
DOI:10.1021/jacs.9b04384
日期:2019.7.31
A novel dynamic kinetic resolution (DKR) of tetrasubstituted alkenyl cyanohydrins prepared from the corresponding α,β-unsaturatedaldehydes is described. The deprotonation of a geometrical mixture of tetrasubstituted alkenyl cyanohydrins with sodium diisopropylamide (NaDA) enables the equilibration of the E- and Z-olefins and the selec-tive functionalization of former to selectively afford the E-adduct
Thermal activation of γ,δ-unsaturated ketones (1, 9 and 12) in the presence of a catalytic amount of propionic acid causes a rearrangement to give new γ,δ-unsaturated ketones (2, 10 and 14)via an intramolecular ene reaction followed by a retro-ene reaction.