Electrochemical Conjugate Additions of the Allyl Groups in Substituted Allyl Halides to α,β-Unsaturated Esters

Article abstract of DOI:10.1246/bcsj.54.3456

Electrolysis of allyl halides and diethyl fumarate (2) in N,N-dimethylformamide containing 0.2 M tetraethylammonium tosylate gave a conjugate addition product, ethyl 3-(ethoxycarbonyl)-5-hexenoate, in a moderate yield.The electrochemical reaction of 1-chloro-3-methyl-2-butene (4) with 2, that of allyl chloride 4 with methyl crotonate (6), and that of methyl 4-halo-2-butenoate with 2 likewise gave the corresponding conjugate addition products, ethyl 3-(ethoxycarbonyl)-6-methyl-5-heptenoate, methyl 3,4,4-trimethyl-5-hexenoate, and ethyl 3-(ethoxycarbonyl)-4-(methoxycarbonyl)-5-hexenoate, respectively.The addition reaction of 4 to 2 takes place at the α-carbon terminus of 4 exclusively, whereas the addition of 4 to 6 at the γ-carbon terminus of 4 .These regioselectivities of the additions and pathways of the reactions are discussed.