Reactions of (1E)-buta-1,3-dien-1-yl acetate with diazocarbonyl compounds

Carbene transfer to appropriate substrates is a highly versatile tool for the construction of carbon frameworks with increased functional and structural complexity. In this study, some novel cyclopropane derivatives were synthesized via carbenoid reactions and their further reactivities were investigated. (1E)-Buta-1,3-dien-1-yl acetate was reacted with four different diazocarbonyl compounds, ethyl diazoacetate, dimethyl diazomalonate, 1-diazo-1-phenylpropan-2-one, and methyl (3E)-2-diazo-4-phenylbut-3-enoate, in the presence of two catalysts. All synthesized substituted cyclopropanes were obtained chemoselectively with respect to less-hindered C=C bonds. Under the applied conditions, while cyclopropanes 7a and 7d underwent further reactions, cyclopropanes 7b and 7c were stable enough. Cyclopropanes 7a and an additional equivalent of ethyl diazoacetate yielded polyfunctionalized cyclohexenes. Cyclopropanes from methyl (3E)-2-diazo-4-phenylbut-3-enoate yielded polyfunctionalyzed cycloheptadiene isomers by Cope rearrangement.