Abstract
In order to clarify the conformation of chromophore in rhodopsin, especially the torsional angle around the C6-C7 single bond, 8, 18-propano- and methano-retinals were prepared from 2, 2-dimethylcyclohexanone via the palladium-catalyzed coupling reaction of vinyl triflates with methyl E-3-trimethylstannyl-2-butenoate, and their interaction with bovine opsin was investigated.