Reactions of diazoalkanes with unsaturated compounds 15. Catalytic reactions of unsaturated carbonyl compounds and their derivatives with diazomethane

Abstract

The present study concerned with the influence of the nature of the acetal fragment in unsaturated compounds on the reactivity of the C=C bond in cyclopropanation reactions with diazomethane catalyzed by copper and palladium compounds. The acetal substituents at the α or γ position with respect to the C=C bond were found to exert an activating effect on the yields of cyclopropanation products compared to the starting unsaturated carbonyl com pounds, which give 1,3 dipolar cycloaddition adducts with CH 2 N 2 as by products. Cyclo propanation of the double bonds appeared to be most efficiently catalyzed by Pd(acac) 2 .

Reactions of diazoalkanes with unsaturated compounds 16. Catalytic reactions of diazomethane with 2-alkenyl-1,3-oxazolidines and 2-alkenyl-1,3-oxathiolanes

“…Re cently, 1 we have shown, that the yield of catalytic cyclo propanation products of unsaturated acetals bearing α or γ positioned acetal function is higher compared to the same reaction of parent unprotected alkenes. This reaction is an efficient approach to cyclopropane con taining carbaldehydes.…”