e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Competitive [4+ 2]-cycloaddition versus [1, 5]-hydrogen sigmatropy in a cycloheptatriene. An efficient route to 3-azatricyclo [5.3. 1.04, 10] undeca-5, 8-diene
…, H Ma, R Raghavachari, SW Szczepanski
Index: Krow, Grant R.; Cannon, Kevin C.; Carey, James T.; Ma, Hong; Raghavachari, Ramesh; Szczepanski, Steven V. Journal of Organic Chemistry, 1988 , vol. 53, # 12 p. 2665 - 2668
Thermal rearrangements of N-acyl-7-aminocyclohepta-1, 3, 5-trienes 7b-e in octane or xylene provide [4+ 21-cycloaddition products 8b-e and [1, 5]-hydrogen sigmatropic rearrangement products 9b-e. The relative rate of formation for &/9e is 1.5 in refluxing octane. At a higher reaction temperature in xylene and longer reaction times, 7b afforded a second hydrogen-shift product lob. No thermal [3, 3]-carbon shift products were observed ...