75839-91-7Relevant academic research and scientific papers
Novel dienes and dienophiles, VI: On the chemical behavior of Z-ethynyl-1,3-butadiene
Hopf, Henning,Jaeger, Helge,Ernst, Ludger
, p. 815 - 824 (2007/10/03)
The behavior of 2-ethynyl-1,3-butadiene (1) as the diene component in Diels-Alder additions has been studied using a selection of representative double and triple bond dienophiles. The latter include maleic anhydride (5a), diethyl fumarate (6), benzoquinone (7), methyl acrylate (11), juglone (20), 1-methylcyclopropene (23), dimethyl acetylenedicarboxylate (26), propiolic aldehyde (32), 4-phenyl-1,2,4-triazolin-3,5-dione (35) and diethyl azodicarboxylate (37). [2 + 4] Cycloadducts were formed in all cases in varying yields. The addition is accompanied by thermal dimerization of 1 which leads to 1,4-diethynyl-4-vinyl-1-cyclohexene (43) and 1,6-diethynyl-1,5-cyclooctadiene (39). The mechanism of this dimerization is discussed. In a competition experiment towards maleic anhydride (5a), diene 1 was shown to be ca. five times less reactive than isoprene. VCH Verlagsgesellschaft mbH, 1996.
Electroorganic Reactions. Part 37. The Stereochemistry and Mechanism of the Cathodic Hydrogenation of Methyl 4-tert-Butylcyclohex-1-enecarboxylate
Matteis, Cristina I. De,Utley, James H. P.
, p. 879 - 883 (2007/10/02)
Methyl 4-tert-butylcyclohex-1-enecarboxylate is hydrogenated at a mercury cathode, in the presence of proton donors, in a smooth 2 F mol-1 process.The proportions of cis and trans isomers in the product (methyl 4-tert-butylcyclohexanecarboxylate) are a function of reaction conditions and detailed consideration shows that the reaction is under kinetic control.Protonation of the first-formed radical anion is probably at C-1, with little stereoselectivity.The results of base- and radical-induced epimerizations of 1,4-disubstituted cyclohexanes were used to establishthe likely outcome of thermodynamic control.These results are in impressive agreement with calculations based on substituent group conformational preferences.
The conformational free energy difference.for the trideuteromethyl substituent in cyclohexane
Booth, Harold,Everett, Jeremy Ramsey
, p. 2714 - 2719 (2007/10/02)
Studies at 169 K to 194 K of the 13C nmr spectrum of cis-1-ethyl--4-methylcyclohexane show that the conformational enthalpy difference -ΔH0 is 1.82 +/- 0.07 kcal mol-1 and the conformational entropy difference ΔS
