Organocatalytic Asymmetric Michael-Hemiacetalization Reaction Between 2‑Hydroxyacetophenones and Enals: A Route to Chiral β,γ-Disubstituted γ‑Butyrolactones

The first highly enantioselective
organocatalytic reaction employing
2-hydroxyacetophenones is disclosed, namely Michael-hemiacetalization
reaction of 2-hydroxyacetophenones with enals. The combination of
a primary amine and a secondary amine catalyst was found to be the
best choice for this methodology. The products of this reaction were
obtained in high enantio- and diastereoselectivities and were converted
to a variety of biologically important γ-butyrolactones.