Double helicenes: Diphenanthro[4,3-a; 3′,4′-o]picene and benzo[s]diphenanthro[4,3-a; 3′,4′-o]picene
作者:R.H. Martin、Ch. Eyndels、N. Defay
DOI:10.1016/s0040-4020(01)97510-6
日期:1974.1
The synthesis and NMR spectra of the title compounds are described. An X-ray diffraction study, carried out by Dr. J. D. Dunitz (ETH, Zurich), showed that the only product isolated from the photocyclisation of 6 has the dl configuration.
Photodehydrocyclizations of stilbene-like compounds—XI
作者:W.H. Laarhoven、Th.J.H.M. Cuppen、R.J.F. Nivard
DOI:10.1016/s0040-4020(01)97511-8
日期:1974.1
The synthesis of a new double helicene, diphenanthro[4.3-a;3′.4′-o]picene, is described. Of the two possible diastereoisomers only one was obtained as a racemate. The compound was partly resolved with TAPA yielding fractions enriched with one or the other enantiomer. They could not be converted into the other diastereomer by heating, but racemized under these conditions at a relatively low temperature