N-heterocyclic carbene catalyzed reaction of enals and 1,2-dicarbonyl compounds: stereoselective synthesis of spiro gamma-butyrolactones.
[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.
Nair
Vijay
V
Organic Chemistry Section, Regional Research Laboratory (CSIR), Trivandrum 695 019, India. vijaynair_2001@yahoo.com
Vellalath
Sreekumar
S
Poonoth
Manojkumar
M
Mohan
Resmi
R
Suresh
Eringathodi
E
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
D000447:Aldehydes; D006838:Hydrocarbons; D013141:Spiro Compounds; C030011:carbene; D007510:Isatin; D015107:4-Butyrolactone; D008697:Methane