Investigation of aliphatic dienes by chemical ionization with nitric oxide
摘要:
AbstractIt is shown that the position of the double bond close to the hydrocarbon end of an aliphatic diene functionalized at C(1) can readily be determined by chemical ionization with NO+. Owing to the low abundance of the ions characteristic for the position of the other double bond, its localization may be difficult. Measurement of the chemical ionization (nitric oxide as reagent gas) spectra of the corresponding epoxides or collision activation studies can help.
conditions atom transfer products (17a–c, 18c,d) were obtained exclusively, whose regio- and stereochemistry were dependant on the olefinic acceptor. Thus, irradiation of the ester trans-16a or the phenyl derivative 16b (E/Z mixture) gives the trans-cyclopentyl derivatives 17a and 17b; the bromide 16c (R=Me) affords a mixture of the trans-cyclopentyl compound 17c and a comparable amount of the cyclohexyl
Investigation of aliphatic dienes by chemical ionization with nitric oxide
作者:H. Budzikiewicz、St. Blech、B. Schneider
DOI:10.1002/oms.1210261205
日期:1991.12
AbstractIt is shown that the position of the double bond close to the hydrocarbon end of an aliphatic diene functionalized at C(1) can readily be determined by chemical ionization with NO+. Owing to the low abundance of the ions characteristic for the position of the other double bond, its localization may be difficult. Measurement of the chemical ionization (nitric oxide as reagent gas) spectra of the corresponding epoxides or collision activation studies can help.
Intramolecular [4+2]-cycloadditions of nitroalkenes with olefins. 2
作者:Scott E. Denmark、Young-Choon Moon、Christopher J. Cramer、Michael S. Dappen、C.B.W. Senanayake
DOI:10.1016/s0040-4020(01)89054-2
日期:1990.1
The intramolecular [4+2]-cycloadditions of di- and trisubstituted nitroalkenes with unactivated olefins are described. The cycloadditions proceed readily at low temperatures in the presence of SnCl4. The reactions are shown to be stereospecific in the preservation of dienophile configuration in the product. The configuration of the heterodiene controls the stereochemistry of the ring fusion but the