Enantioselective direct vinylogous aldol-cyclization cascade reaction between β,γ-unsaturated amides and o-quinones

Org Biomol Chem. 2016 Jul 6;14(27):6435-41. doi: 10.1039/c6ob00893c.

Abstract

1,2-Diketones are employed, for the first time, as electrophiles in the vinylogous aldol reaction. With 5 mol% of chiral tertiary amine-thiourea , a direct vinylogous aldol-cyclization cascade reaction between β,γ-unsaturated amides and o-quinones has been achieved to produce spirocyclic dihydropyranones in 76-99% yield and 82-95% ee.