Process For the Manufacture of Substituted Propionic Acids
申请人:McCormack Peter
公开号:US20080242876A1
公开(公告)日:2008-10-02
The invention concerns a process for the manufacture of substituted propionic acids comprising providing a substrate of formula (I): And subjecting the substrate to enantioselective hydrogenation under enantioselective hydrogenation conditions in the presence of an enantioselective hydrogenation catalyst comprising a catalyst ligand having a metallocene group with a chiral phosphorus or arsenic substituent to provide in enantiomeric excess a product of formula (II): or its enantiomer or if applicable its diastereomer.
Reductive lithiation of alkyl 2-thiopyridyl ethers to generate optically pure α-alkoxylithium reagents
作者:Scott D. Rychnovsky、Kevin Plzak、Dacia Pickering
DOI:10.1016/0040-4039(94)85008-9
日期:1994.9
Enantiomerically pure 4-lithio-2-alkyl-1,3-dioxanes, 11 and 13, were prepared by reductivelithiation of alkyl2-thiopyridylether 10, which was in turn prepared by Barton radical decarboxylation of the homologous acid. The optical activity was introduced by chirality transfer to and from the stereogenic acetal center.