136962-28-2Relevant academic research and scientific papers
Palladium-catalyzed allylation of α-hydroxy acids
Moorlag, Henk,Vries, Johannes G. de,Kaptein, Bernard,Schoemaker, Hans E.,Kamphuis, Johan,Kellogg, Richard M.
, p. 129 - 137 (2007/10/02)
Mandelic and lactic acids are converted to the 1,3-dioxolan-4-ones by treatment with acetone dimethyl acetal.Deprotonation followed by treatment with an allyl acetate and a catalytic amount (1 mol percent) of palladium catalyst afforded the allylated dioxolanones, which could be hydrolyzed to the corresponding α-allyl α-hydroxy acids.The lithium enolate of the dioxolanone of mandelic acid was also coupled with methallyl, cinnamyl, geranyl and (E)-1-methyl-2-butenyl acetates.The zinc enolate of the dioxolanone of lactic acid reacted smoothly with allyl acetate in a catalyzed reaction whereas no detectable reaction was observed when the lithium enolate was used.This appears to be the result of complications arising from the enhanced basicity of the lithium compared to zinc enolate.Various attempts were made to achieve enantioselectivity using chiral ligands on the palladium catalyst.The zinc enolates were found to provide better results although the enantioselectivity was only modest, about 30percent enantiomeric excess being the best result obtained.Chiraphos proved to be the best optically active ligand of a variety tested.
PLE catalyzed hydrolyses of α-substituted α-hydroxy esters: The influence of the substituents
Moorlag,Kellogg
, p. 705 - 720 (2007/10/02)
The enzymatic hydrolyses of a variety of α-substituted mandelic and lactic esters using pig liver esterase (PLE) have been investigated. High to moderate enantioselectivity was found for various α-substituted mandelic esters, whereas PLE showed low to no enantioselectivity for α-substituted lactic esters. We observed that the enantioselectivity of PLE depends strongly on the length and nature of the substituent at the α-position. Some sequences for an active site model of PLE are discussed.
