877-06-5Relevant articles and documents
Story
, p. 2085 (1960)
C3-Symmetric Tricyclo[2.2.1.02,6]heptane-3,5,7-triol
Kozel, Volodymyr,Daniliuc, Constantin-Gabriel,Kirsch, Peer,Haufe, Günter
supporting information, p. 15456 - 15460 (2017/11/13)
A straightforward access to a hitherto unknown C3-symmetric tricyclic triol both in racemic and enantiopure forms has been developed. Treatment of 7-tert-butoxynorbornadiene with peroxycarboxylic acids provided mixtures of C1- and C3-symmetric 3,5,7-triacyloxynortricyclenes via transannular π-cyclization and replacement of the tert-butoxy group. By refluxing in formic acid, the C1-symmetric esters were converted to the C3-symmetric formate. Hydrolysis gave diastereoisomeric triols, which were separated by recrystallization. Enantiomer resolution via diastereoisomeric tri(O-methylmandelates) delivered the target triols on a gram scale. The pure enantiomers are useful as core units of dopants for liquid crystals.
Photodissociation Dynamics of Cyclopropenylidene, c-C3H2
Schuurman, Michael S.,Giegerich, Jens,Pachner, Kai,Lang, Daniel,Kiendl, Benjamin,MacDonell, Ryan J.,Krueger, Anke,Fischer, Ingo
supporting information, p. 14486 - 14495 (2015/10/05)
In this joint experimental and theoretical study we characterize the complete dynamical "life cycle" associated with the photoexcitation of the singlet carbene cyclopropenylidene to the lowest lying optically bright excited electronic state: from the initial creation of an excited-state wavepacket to the ultimate fragmentation of the molecule on the vibrationally hot ground electronic state. Cyclopropenylidene is prepared in this work using an improved synthetic pathway for the preparation of the precursor quadricyclane, thereby greatly simplifying the assignment of the molecular origin of the measured photofragments. The excitation process and subsequent non-adiabatic dynamics have been previously investigated employing time-resolved photoelectron spectroscopy and are now complemented with high-level ab initio trajectory simulations that elucidate the specific vibronic relaxation pathways. Lastly, the fragmentation channels accessed by the molecule following internal conversion are probed using velocity map imaging (VMI) so that the identity of the fragmentation products and their corresponding energy distributions can be definitively assigned.
Ruthenium(II)-catalyzed [2+2] cycloadditions of anti 7-substituted norbornenes
Jordan, Robert W.,Le Marquand, Paul,Tam, William
, p. 80 - 86 (2008/09/17)
The ruthenium(II)-catalyzed [2+2] cycloadditions of anti 7-substituted norbornenes with an alkyne were investigated. The cycloadditions were found to proceed with a high degree of stereoselectivity, giving only the exo stereoisomers in moderate to good yields using an improved protocol. Comparative rate studies between a variety of anti 7-substituted norbornenes and an alkyne revealed that the reactivity of the alkene component decreases dramatically as the alkene becomes more electron deficient. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.