129286-24-4

Upstream product

• 591-87-7 Allyl acetate 
• 6337-34-4 2,2-dimethyl-5-phenyl-1,3-dioxolan-4-one 
• 106-95-6 allyl bromide 
• 611-71-2 MANDELIC ACID 

Downstream Products

• 20978-66-9 ethyl 2-hydroxy-2-phenyl-4-pentanoate 
• 89358-17-8 2-phenylpent-4-ene-1,2-diol 
• 495-41-0 1-phenylbut-2-en-1-one 
• 6249-80-5 1-phenylbut-3-en-1-one 
• 129388-29-0 (R)-2-Hydroxy-2-phenyl-pent-4-enoic acid ethyl ester 
• 81037-04-9 (2S)-2-hydroxy-2-phenyl-4-pentenoic acid 
• 62696-41-7 (R)-2-Hydroxy-2-phenyl-4-pentenoic Acid 
• 73698-05-2 (S)-2-Hydroxy-2-phenylpentanoic Acid 

Relevant academic research and scientific papers

Nucleophilic benzoylation using a mandelic acid dioxolanone as a synthetic equivalent of the benzoyl carbanion. Oxidative decarboxylation of α-hydroxyacids

The synthesis of alkyl aryl ketones using a mandelic acid dioxolanone as a synthetic equivalent (Umpolung) of the benzoyl carbanion is reported. The methodology involves alkylation of the mandelic acid dioxolanone, hydrolysis of the dioxolanone moiety in the alkylated products and oxidative decarboxylation of the resulting α-hydroxyacids. The last step is carried out in a catalytic aerobic way using a Co (III) complex in the presence of pivalaldehyde under very mild conditions.

Behaviour of dioxolanones as chiral acyl anion equivalents

The 1,3-dioxolan-4-ones readily derived from α-hydroxy acids act as convenient acyl anion equivalents by deprotonation - alkylation followed by flash vacuum pyrolysis. Conjugate addition of their anions to ethyl crotonate similarly gives β-methyl-γ-oxo esters and by using chiral dioxolanones these can be obtained in up to 86% e.e.

Lipase AKG mediated resolutions of α,α-disubstituted 1,2-diols in organic solvents; remarkably high regio- and enantio-selectivity

Diols 1, which contain adjacent tertiary and primary hydroxy groups, can be selectively mono-acylated at the primary hydroxy group by many lipases in organic solvents. Since the reaction does not take place at the chiral tertiary centre itself, observed enantioselectivities are usually low. Only the combination of one lipase, lipase AKG (Amano, Pseudomonas sp.), with selected substrates gives high enantioselectivities (E 20 to > 200). Also, the solvent and acyl donor employed influences the outcome. On the basis of the results of lipase AKG towards substrates 1 an active site model for this specific lipase has been developed, which can account for the results obtained. Full experimental details on the synthesis of diols 1 and enzymatic preparation of acetates 2 are given. Also, the absolute stereochemistry of the enzymatically prepared diols 1 has been established by independent synthesis from (R)-mandelic acid.

Palladium-catalyzed allylation of α-hydroxy acids

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.

Pig Liver Esterase Catalyzed Hydrolyses of Racemic α-Substituted α-Hydroxy Esters

Pig liver esterase catalyzed hydrolyses of some α-substituted α-hydroxy esters give product acids and recovered esters in 9-94percent enantiomeric excess.The observed enantiomeric selectivity could be rationalized using a recently proposed active site mod