Easy access to medium rings by entropy/strain reduction. Part 2. The ready availability of cis,cis-2,4-diene-1,6-diols and derived dibromides allows a simple and mild route to substituted 2,7-dihydro-1H-azepines
Efficient synthesis of unsaturated seven-membered rings by an entropy/strain reduction strategy: 2,7-dihydro-1H-azepines, -oxepines, -thiepines, -1H-phosphepine and 1,3-cycloheptadienes