α-Alkylation of α, β-Unsaturated Ketones via N, N-Dimethylhydrazones

Abstract

The alkylation of 3-methyl-2-cyclopenten-1-one N, N-dimethylhydrazone was investigated and was found to mone and cis-jasmone were prepared in good yield. Isophorone dimethylhydrazone was also alkylated at the a-position, but for ionone dimethylhydrazone, the reaction occured at the a'-position (methyl carbon), not the a-position of the hydrazone.

Synthesis of 2-Alkyl-2-methyl-3-butenenitriles by Alkylation of 2-Methyl-2-butenal N,N-Dimethylhydrazone

“…1 The alkylation of aldehydes or ketones as N,N-dimethylhydrazones have been widely used to synthesize variety of organic compounds such as terpenes 2 and pheromones. 3 We have previously reported the alkylation of N,N-dimethylhydrazones of various R,βunsaturated aldehydes gave R-alkylated β,γ-unsaturated aldehydes N,N-dimethylhydrazones with double bond migration. 4 We now wish to describe a novel synthesis of 2-alkyl-2-methyl-3-butenenitriles 4, which have a flexible quaternary carbon atom at R-position, by the foregoing reaction sequence (Scheme 1).…”

“…In the case of elimination, there is the conversion of aldehyde N,N -dimethylhydrazones to nitriles with magnesium monoperoxyphthalate (MMPP) . The alkylation of aldehydes or ketones as N,N -dimethylhydrazones have been widely used to synthesize variety of organic compounds such as terpenes and pheromones . We have previously reported the alkylation of N,N -dimethylhydrazones of various α,β-unsaturated aldehydes gave α-alkylated β,γ-unsaturated aldehydes N,N -dimethylhydrazones with double bond migration .…”