On the problem of regioselectivity in the 1, 3-dipolar cycloaddition reaction of munchnones and sydnones with acetylenic dipolarophiles

A Padwa, EM Burgess, HL Gingrich…

Index: Padwa, Albert; Burgess, Edward M.; Gingrich, Henry L.; Roush, David M. Journal of Organic Chemistry, 1982 , vol. 47, # 5 p. 786 - 791

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Citation Number: 64

Abstract

The l, 3-dipolar cycloaddition reaction of several unsymmetrically substituted munchnones and sydnones with methyl propiolate has been examined. The initially formed cycloadducts readily extrude carbon dioxide to produce five-membered heteroaromatic ring compounds. The reaction of sydnones with methyl propiolate produced a mixture of regioisomeric pyrazoles. The analogous [3+ 21 cycloaddition reaction of munchnones with methyl ...