35781-54-5Relevant academic research and scientific papers
ERYTHRO SELECTIVE CROSS ALDOL REACTION VIA α-SILYL TRIMETHYLSILYL ESTERS.
Bellassoued, Moncef,Dubois, Jacques-Emile,Bertounesque, Emmanuel
, p. 2623 - 2626 (1986)
Various fluoride ion mediated reactions of aliphatic α-silyl trimethylsilyl esters 1 with benzaldehyde have been investigated.Moderate erythro stereoselectivity is observed.
Indenone synthesis. Improved synthetic protocol and effect of substitution on the intramolecular Friedel-Crafts acylation
Galatsis, Paul,Manwell, Jeffrey J.,Blackwell, James M.
, p. 1656 - 1659 (2007/10/02)
An improved protocol for the construction of substituted indenones is presented. Also the effect of substitution on the intramolecular Friedel-Crafts acylation was noted. Specifically, if there is no substitution at the 2-position of the indenone poor yields of cyclized material were obtained, if at all, while the substitution of a methyl or ethyl group greatly improved the yield of cyclized material. Placement of a large group (e. g., benzyl) resulted in a diminuation of the improved yield. The new synthetic procedure could, in principle, allow for the construction of 2,3-disubstituted indenones. One example of this reaction mode was presented.
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
Mulzer, Johann,Zippel, Matthias,Bruentrup, Gisela,Segner, Johannes,Finke, Juergen
, p. 1108 - 1134 (2007/10/02)
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.
