86042-91-3Relevant academic research and scientific papers
δ-LACTONES FROM δ-KETOESTERS-II; MECHANISM CHANGES IN ALKYLATION REACTIONS AND SUBSTITUENT EFFECTS ON STEREOSELECTION
Maio, G. Di,Vecchi, E.,Zeuli, E.,Delfini, M
, p. 749 - 756 (2007/10/02)
Alkylation of methyl 4-methyl 5-oxo 5-phenyl (m and p-X substituted) pentanoates 1a-h give cis and trans tetrahydro 5,6-dimethyl 6-phenyl 2H pyran-2-ones.LFER of isomer ratios as function of the X substituent on the phenyl ring is seen in MeLi-Et2O.The lactone ratios of the reactions in THF with MeMgCl are not affected by the X phenyl substituent, while a more complex situation is showed by reactions of MeMgCl in Et2O and benzene.Changes in the cis: trans-ratios with variations in reactant and solvent are discussed in terms of equilibrium between folded and unfolded conformations in transition states.
ALKYLATION OF δ-KETOESTERS : A MECHANISM CHANGE DEPENDING ON CONFORMATIONAL MOBILITY AND SUBSTITUENT EFFECTS ON STEREOSELECTION.
Di Maio, G.,Vecchi, E.,Zeuli, E.
, p. 5211 - 5214 (2007/10/02)
Kinetic evidence shows that the two groups of a δ-ketoester can interact in the transition state of a Grignard reaction.This promotes high stereoselectivity by chiral center far from the ketonic group and produces good correlations between stereoselection and electronic effects of substituents.
