62322-49-0Relevant academic research and scientific papers
Synthesis of optically active α-methylene γ-lactones through lipase-catalyzed kinetic resolution
Adam, Waldemar,Groer, Peter,Saha-Moeller, Chantu R.
, p. 2239 - 2243 (2007/10/03)
The lipase-catalyzed kinetic resolution of the γ-hydroxy esters 1a,b and their subsequent acid-mediated cyclization afford the optically active α-methylene γ-lactones 2a,b in high yields (71-89%) and in up to 95% enantiomeric excess. The direct enzymatic
SYNTHESIS OF OPTICALLY PURE α-METHYLENE-γ-LACTONES FROM (+)-R-(4-METHYLPHENYL)-ALKYLSULPHOXIDES
Bravo, Pierfrancesco,Resnati, Giuseppe,Viani, Fiorenza
, p. 2913 - 2916 (2007/10/02)
Optically pure (+)-R-(4-methylphenyl)sulphoxides were lithiated and alkylated with lithium α-bromomethyl acrylate with medium to high diastereoselection; condensation products gave in two steps optically pure α-methylene-γ-lactones.
Allergenic α-Methylene-γ-butyrolactones. Stereospecific Syntheses of (+)- and (-)-γ-Methyl-α-methylene-γ-butyrolactones. A Study of the Specificity of (+) and (-) Enantiomers in Inducing Allergic Contact Dermatitis
Barbier, Pierre,Benezra, Claude
, p. 943 - 946 (2007/10/02)
The enantiomers of γ-methyl-α-methylene-γ-butyrolactone have been prepared stereospecifically from (R)- and (S)-glutamic acid.Three groups of guinea pigs have been sensitized (Feund complete adjuvant technique) to the (+)-isomer, the (-)-isomer, and the (+/-)-mixture.The animals have been tested with each of the enantiomers and with a mixture of the compounds.Only the (-) enantiomer showed some specificity: guinea pigs sensitized to this enantiomer react weakly to the other compound; in turn, animals sensitized to the (+) enantiomer react similarly to both antipodes.Interestingly, reaction to the (+/-) mixture in each group of guinea pigs was the sum of skin responses to the individual enantiomer.These results should be contrasted with sensitization to (+)- and (-)-frullanolides, sesquiterpene lactones for which strong stereospecificity was observed.
Palladium-Catalyzed Carbonylation of Vinyl Halides: A Route to the Synthesis of α-Methylene Lactones
Martin, Larry D.,Stille, J. K.
, p. 3630 - 3633 (2007/10/02)
α-Methylene γ-lactones were synthesized in high yields by the palladium-catalyzed carbonylation reactions of alkyl-substituted 3-bromobut-3-en-1-ols under mild conditions.The bromo alcohols were obtained by the reaction of magnesium bromide with various epoxides followed by conversion of the trimethylsilyl group to bromide.By starting with optically active epoxides such as (R)-1,2-epoxypropane or (2R,3R)-2,3-epoxybutane, the corresponding lactones could be obtained virtually optically pure.The carbonylation reaction is selective in that it generates only γ-lactones when there is a choice of two vinylic iodides or two alcohols that could lead either to the five- or six-membered rings.
