Highly stereoselective epoxidation of alpha-methyl-gamma-hydroxy-alpha,beta-unsaturated esters: rationalization and synthetic applications.
The diastereoselectivity of the nucleophilic epoxidation of gamma-hydroxy-alpha,beta-unsaturated esters having a methyl substituent at the alpha- or beta-position was investigated. Epoxidation of the alpha-methyl-substituted enoate was highly stereoselective, giving rise to the syn isomer. This finding was used to perform an enantioselective synthesis of a natural product having a beta-hydroxy-alpha-methylene-gamma-butyrolactone motif. The nucleophilic epoxidation of enoates was found to be irreversible. Models to explain the observed stereoselectivities are proposed.
López
Irakusne
I
Departament de Química Inorgànica i Orgànica Universitat Jaume I, 12080 Castelló, Spain.
Rodríguez
Santiago
S
Izquierdo
Javier
J
González
Florenci V
FV
D004852:Epoxy Compounds / Q000737:chemistry*; D004952:Esters / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared; D013237:Stereoisomerism
D004852:Epoxy Compounds; D004952:Esters