The organocatalytic enantio- and diastereoselective cycloetherification of 1,3-cyclohexanedione-bearing enones involving the in situ generation of chiral cyanohydrins was developed. This transformation offers the first catalytic asymmetric approach to oxadecalin derivatives containing contiguous tetrasubstituted chiral carbons at the bridge heads of the fused ring systems. Depending on substituents
作者:Lisa M. Schneider、Volker M. Schmiedel、Tommaso Pecchioli、Dieter Lentz、Christian Merten、Mathias Christmann
DOI:10.1021/acs.orglett.7b00836
日期:2017.5.5
A modular synthesis of functionalized carbocyclic propellanes was developed. Formation of the first of two quaternary bridgehead centers has been achieved by desymmetrization of prostereogenic ketones by either Hajos–Parrish–Eder–Sauer–Wiechert-type processes or Werner’s catalytic asymmetric Wittig reaction. The obtained bicyclic enones were subjected to conjugate additions upon which the remaining