title: N-heterocyclic carbene catalyzed reaction of enals and 1,2-dicarbonyl compounds: stereoselective synthesis of spiro gamma-butyrolactones.
abstract: [reaction: see text]. Nucleophilic heterocyclic carbene (NHC) catalyzed annulation of enals and cyclic 1,2-dicarbonyl compounds, opening a route to gamma-spirolactones, has been observed for the first time. The strategy works well with isatins, leading to spiroannulated oxindole derivatives. It is conceivable that the spiroannulation protocol reported herein will be applicable to the synthesis of important natural products that are endowed with a spiro gamma-butyrolactone motif, especially oxindoles and norsesquiterpenoids.
authors.affiliation: Organic Chemistry Section, Regional Research Laboratory (CSIR), Trivandrum 695 019, India. vijaynair_2001@yahoo.com
authors.forename: Vijay
authors.initials: V
authors.lastname: Nair
authors.forename: Sreekumar
authors.initials: S
authors.lastname: Vellalath
authors.forename: Manojkumar
authors.initials: M
authors.lastname: Poonoth
authors.forename: Resmi
authors.initials: R
authors.lastname: Mohan
authors.forename: Eringathodi
authors.initials: E
authors.lastname: Suresh
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D006838:Hydrocarbons / Q000737:chemistry; D007510:Isatin / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000447:Aldehydes; D006838:Hydrocarbons; D013141:Spiro Compounds; C030011:carbene; D007510:Isatin; D015107:4-Butyrolactone; D008697:Methane