5457-09-0Relevant articles and documents
SYNTHETIS OF CYCLIC AND ACYCLIC β,γ-UNSATURATED CARBOXYLIC ACIDS VIA AN E1-TYPE IONIZATION/ELIMINATION OF β-LACTONES
Black, T. Howard,Eisenbeis, Shane A.,McDermott, Todd S.,Maluleka, Stephen L.
, p. 2307 - 2316 (2007/10/02)
Cyclic and acyclic ketones were converted in three steps into 3-alkenoic acids, bearing a variety of substituents in the α-position.The sequence, involving ionization/elimination of a β-lactone, affords high yields of pure products uncontaminated with conjugated isomers.Support for an E1-type mechanism is also provided.
AN EFFICIENT, HIGHLY REGIOSELECTIVE SYNTHESIS OF SUBSTITUTED (1-CYCLOHEXENYL) ACETIC ACID DERIVATIVES VIA IONIZATION/ELIMINATION OF β-LACTONES
Black, T. Howard,Maluleka, Stephen L.
, p. 531 - 534 (2007/10/02)
When treated with magnesium bromide, spiro β-lactones undergo an ionization/elimination reaction to afford cyclohexenyl acetic acid derivatives in high yield and isomeric purity.
Kinetics and Mechanism of the Ivanov Reaction: Reaction of Aldehydes and Ketones with Phenylacetic Acit Magnesium Enediolate
Toullec, Jean,Mladenova, Margarita,Gaudemar-Bardone, Francoise,Blagoev, Blagoi
, p. 2563 - 2569 (2007/10/02)
Stopped-flow kinetics of the reaction between aldehydes or ketones and the magnesium enediolate of phenylacetic acid in THF are second order at enediolate concentrations -3 M.At concentrations of 10-3 - 3*10-2 M, the formation of a bis(enediolate) requires a more complex kinetic equation.Second-order rate constans are reported for the reaction of the enediolate with a number of aldehydes and ketones at 25 deg C.Entropies of activation for cyclohexanone, benzaldehyde, 2-methylpropanal, and 2,2-dimethylpropanal are positive, and enthalpy-entropy compensation is observed.Ef fects of cycloalkanone ring size and benzaldehyde substituents are small and are ascribable to a transition state with a very small C-C bond order.A two-step mechanism is proposed, with preequilibrium formation of a coordination intermediate which, in some cases, is accompanied by a change in the magnesium coordination number.Effects of alkyl groups on aldehyde and ketone reactivity stem mainly from steric desolvation.