Ethylene derivatives cyclopropanes

The first nonintroductory section of the text starts with the observation made early in this century that cyclopropanes have significant olefinic character. That is, corresponding ethylene and cyclopropane derivatives have significant similarities. There are literature comparisons of the thermochemistry of direct counterparts such as the parent species (1 and 2, X = H), propene and methylcyclopropane with X = Me, and of methyl acrylate and methyl cyclopropanecarboxylate 8 with X = COOMe. But the chemistry of substituted eth-ylenes is far richer than just that of vinyl compounds. One can retrieve enthalpy of formation data for cumulenes ( cumulenated olefins) such as allene (3) and both cis- and trans-2,3,4-hexatriene (4a and 4b), and for conjugated olefins such as 1,3-butadiene (5) and both (Z)- and (E)-1,3,5-hexatriene (6a and 6b). For the cyclopropane chemist it is natural to... 

Irradiation Cyclopropanes from ethylene derivatives and alkylidenephosphoranes... 

Cyclopropanes from ethylene derivs. and diazo compds. 

Substitution of the ethylenic carbons in a conjugated enyne by either an electropositive group in the 3-position or by an electronegative group in the 4-position favors addition to the acetylenic group. G. F. Bettinetti, G. Desimoni, and P. Griinanger, G. 94, 91 (1964) cyclopropane ring from ethylene derivatives in methanol s. F. Wessely and A. Eitel, M. 95, 1577 (1964). 

Sodium hydride dimethyl sulfoxide Ring closures with sulfoxonium and sulfonium salts Synthesis of oxido compounds from oxo compounds Cyclopropanes from ethylene derivatives... 

Ethylene derivatives from cyclopropane ring with deearhoxylation... 

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