Optically active keto stabilized sulfur ylide was synthesized from L-proline. The reactions of the ylide With methyl acrylate and methyl vinyl ketone afforded 1,2-disubstituted cyclopropanes. In the case of acrylonitrile, a mixture of 1.2- and 1,1-disubstituted cyclopropanes was obtained. Acylation of the ylide with acetic anhydride gave twice stabilized sulfur ylide.
Optically active keto stabilized sulfur ylide was synthesized from L-proline. The reactions of the ylide With methyl acrylate and methyl vinyl ketone afforded 1,2-disubstituted cyclopropanes. In the case of acrylonitrile, a mixture of 1.2- and 1,1-disubstituted cyclopropanes was obtained. Acylation of the ylide with acetic anhydride gave twice stabilized sulfur ylide.
pyrazole derivatives in a regioselective [3+2] cycloaddition. The reactions occurred at 60 °C in THF solution in the absence of a catalyst. However, diethyl ethynylphosphonate reacted significantly slower than the carboxylates. The obtained products were shown to exist in CDCl3 solution at roomtemperature as mixtures of rotamers. The reactions of diethyl ethynylphosphonate with a selected cyclic α-oxodiazo