(+)-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.
Palladium-catalyzed carbonylation of vinyl halides: a route to the synthesis of .alpha.-methylene lactones
作者:Larry D. Martin、J. K. Stille
DOI:10.1021/jo00140a007
日期:1982.9
Allergenic .alpha.-methylene-.gamma.-butyrolactones. Stereospecific synthesis of (+)- and (-)-.gamma.-methyl-.alpha.-methylene-.gamma.-butyrolactones. A study of the specificity of (+) and (-) enantiomers in inducing allergic contact dermatitis
作者:Pierre Barbier、Claude Benezra
DOI:10.1021/jm00350a011
日期:1982.8
The enantiomers of gamma-methyl-alpha-methylene-gamma-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.