Derivation of a diazabicyclo[3.2.0]heptadiene from a diazatricyclo [4.1.0.02,7] heptene.

Trifluoromethylated 3,5-diazatricyclo[4.1.0.0^2,7]hept-3-ene was converted thermally or photochemically to 2,4-diazabicyclo[3.2.0]hepta-2,6-diene compound. The latter was photolyzed to an imidazole compound.     

An INDO-LMO and 13C NMR spectroscopic study of the C-H bonds in tetracyclo[3.2.0.02,7.04,6]heptane (quadricyclane) and tricyclo[3.1.0.02,4]hexane

Using an INDO approximation to Von Niessen's charge density localization method, the percent s character of the C atom hybrid orbitals engaged in C-H bonds is computed for a series of open-chain and cyclic saturated and unsaturated hydrocarbons. A semi-empirical linear relationship is found between these quantities and the experimental nuclear spin-spin coupling constants J_CH (standard deviation 4·98 Hz). The experimental values of J_CH were measured for quadricyclane (1) and tricyclo[3.1.0.0^2,4]hexane (2) and were shown to be in fair agreement with the theoretical predictions. An analogous relationship is also established between the percent s character of the involved C atom hybrid orbital and the C-H bond distance, the standard deviation being 0·0040Å. This relation is used in order to predict the different C-H bond lengths in the vibrational ground state of 1 and 2, for which equal CH distances were assumed in the analysis of electron diffraction experiments. The results indicate that molecular geometries can be refined with the use of semi-empirical correlations of the above mentioned type.     

Polymerisation von 6,6-Dimethyltricyclo[6.4.0.02,7 dodec-3-ylmethacrylat

Ohne Zusammenfassung     

Rearrangement of substituted tricyclo[2.1.0.02,5]pentan-3-ones

Treatment of 1,5-bis(hydroxymethyl)tricyclo[2.1.0.0^2,5]-pentan-3-one (III) with triphenyl phosphine and carbon tetrachloride results in deep-seated rearrangement to the keto furan, 3-oxybicyclo-[3.3.0]octa-1,4-dien-7-one, VI; the analogous reaction with carbon tetrabromide is normal and yields, the anticipated dibromide IV. Cyclopentadienone intermediates account for the latter reaction and for a dimer formed from 1,5-dimethyltricyclo[2.1.0.0^2,5] pentanone (Ia) upon treatment with iodine.