作者:Paul J. Kropp、Norbert J. Pienta、Joy A. Sawyer、Richard P. Polniaszek
DOI:10.1016/s0040-4020(01)92370-1
日期:——
The previously observed cyclopropaoation of alkenes by irradiation of diiodomethane (I) in their presence has been studied in more detail and found to be a synthetically useful procedure which is significantly less subject to steric effects than the traditional Simmons-Smith method. The results from photocyclopropanation of a variety of alkenes are summarized in Tables 1 and 3–4. In a number of cases
Enthalpies of formation of cis- and trans-1,2-diethylcyclopropane and cis- and trans-bicyclo[6.1.0]nonane. Structural effects on energies of cyclopropane rings
作者:Kenneth B. Wiberg、Elmer C. Lupton、David J. Wasserman、Armin De Meijere、Steven R. Kass
DOI:10.1021/ja00318a032
日期:1984.3
enthalpies of formation of cis- and trans-1,2-diethylcyclopropane were determined by oxygen bomb calimetry. The cis-diethyl isomer was 1.1 kcal/mol less stable than the trans isomer. Alkyl groups were found to stabilize a cyclopropanering by the same amount as for a carbon-carbon double bond. The enthalpies of formation cis- and trans-bicyclo(6.1,0)nonane formation, in contrast to cis- and trans-cyclooctene