2, 3-Disubstituted γ-Butyrolactams from the<i>Michael</i>-Additions of Doubly Deprotonated, Optically Active β-Hydroxycarboxylates to Nitroolefins. Preliminary Communication
作者:Max Züger、Thomas Weller、Dieter Seebach
DOI:10.1002/hlca.19800630727
日期:1980.10.29
The conjugate addition of the chiral, non-racemic alkoxy-enolates 5 and 6 to nitroolefins furnishes the hydroxynitroesters 7–13, which are catalytically hydrogenated to give the lactams 14–18. The configuration of adduct 7 from nitroethylene was elucidated by NMR. analysis of the acetal 20 derived from 7. The assignment establishes that the reaction follows the stereochemical rule of attack depicted