75245-37-3

Upstream product

• 104-87-0 4-methyl-benzaldehyde 
• 33398-52-6 α-(1-Hydroxy-2,2-dimethylpropyl)benzenessigsaeure 
• 33398-52-6 erythro-3-Hydroxy-4,4-dimethyl-2-phenylvaleriansaeure 
• 95777-19-8 phenylacetic acid magnesium enediolate 
• 620-23-5 m-tolyl aldehyde 
• 103-82-2 phenylacetic acid 
• 630-19-3 pivalaldehyde 

Relevant academic research and scientific papers

Kinetics and Mechanism of the Ivanov Reaction: Reaction of Aldehydes and Ketones with Phenylacetic Acit Magnesium Enediolate

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.

Stereochemistry of the Addition of Carboxylic Acid Dianions to Aldehydes under Kinetic and Thermodynamic Control - Synthesis and Configurational Assignment of 2,3-Disubstituted threo- and erythro-3-Hydroxycarboxylic Acids

Under kinetically controlled conditions (-50 deg C, 10 min) the carboxylic dianions 2 add to aldehydes 3 to give the threo/erythro-adducts 4/5 (Scheme 1); the threo-selectivity markedly increases with the bulkiness of the substituents of 2 or 3 and decreases with the charge/radius ratio of the counter-ions of 2.From these results a syn-transition state with a HOMO-LUMO ineraction between 2 and 3 is derived (Scheme 3).For appropriate substituents a far higher threo-selectivity is observed under thermodynamically (22-50 deg C, 1-3 days) than under kinetically controlled conditions.We describe the isolation of the hydroxy acids 6 and 7, which are formed from 4 and 5 on acidic hydrolysis, and show how their configurations can be unambiguously assigned on the basis of 1H-NMR data.