Organocatalytic Remote Asymmetric Inverse‐Electron‐Demand Oxa‐Diels‐Alder Reaction of Allyl Ketones with Isatin‐Derived Unsaturated Keto Esters
作者:Ye Lin、Xi‐Qiang Hou、Bing‐Yu Li、Da‐Ming Du
DOI:10.1002/adsc.202001242
日期:2020.12.22
A remote cascadeasymmetric inverse‐electron‐demand oxa‐Diels‐Alder reaction of allyl ketones with isatin‐derived β,γ‐unsaturated α‐keto esters has been developed in the presence of a chiral bifunctional squaramide catalyst. Taking advantage of the secondary amide activating group, a series of enantioenriched 3,4’‐pyranyl spirooxindole derivatives bearing three contiguous chiral centers were attained
An efficient two-step no purification protocol for the synthesis of enolizable α-subtituted β,γ-unsaturated aldehydes is reported. The developed strategy involves two steps, epoxidation and Meinwald rearrangement, to result in a formal one-carbon homologation of α,β-unsaturatedaldehydes enabling the insertion of a CHR unit.