REACTIONS OF ENONE ETHYLENE KETALS WITH METHYL DIAZOMALONATE BIS(ACETYLACETONATO)COPPER(II)/

Several cyclic and acyclic enones and their ethylene ketals/acetals we re reacted with dimethyl diazomalonate under bis(acetylacetonaro)coppe r(II) catalysis. Cyclohex-2-en-1-one (1) yielded only C-H insertion pr oducts 2 and 3, whereas but-3-en-2-one gave a cyclopropane albeit in v ery low yield. The ethylene ketals 6 of cyclopent-2-en-1-one and cyclo hex-2-en-1-one gave the corresponding cyclopropanes 7, which were in t urn cleaved to the ketones 8. The acetals 9 and 10 of crotonaldehyde ( (E)-but-2-enal) and cinnamaldehyde ((E)-3-phenylprop-2-enal), respecti vely, yielded C-O insertion and [2,3]-sigmatropic rearrangement produc ts 11b, c and 12b,c, as well as cyclopropanes 11a and 11b, all of whic h are polyfunctional and synthetically useful compounds.