M. Node et al., AN IMPROVED ASYMMETRIC NITROOLEFINATION OF ALPHA-ALKYL-GAMMA-LACTONESAND DELTA-LACTONES WITH MODIFIED NITROENAMINES, Tetrahedron letters, 36(1), 1995, pp. 99-102
New chiral nitroenamines 4a, b were found to be very effective for asy
mmetric nitroolefination of alpha-alkyl-gamma- and delta-lactones. The
enantiomeric excess of the product ran up to 99%. A possible chelatio
n model for the transition state of the asymmetric nitroolefination wa
s discussed.